This Report describes the recently enacted mask ban in California and the proposed laws in other states. Under existing precedent, mask bans are neither clearly prohibited nor clearly permissible. This Report also provides an overview of other options states may have to address masking by federal law enforcement.
As the federal government ramps up immigration enforcement under President Trump’s second administration, federal agents sometimes conduct operations while wearing masks or other face coverings to disguise their identities.1 In March 2025, for example, six ICE agents in street clothes and masks arrested a Tufts graduate student and put her in an unmarked vehicle.2 Masked agents have also arrested parents in daycare parking lots3 and shot into civilian cars.4 Earlier this year, masked ICE and CBP agents shot and killed Renee Nicole Good and Alex Pretti in Minneapolis.5
Members of Congress have introduced federal legislation to prohibit this practice,6 but the odds of enactment appear low. A growing number of states and localities have responded by considering and beginning to adopt their own laws to restrict masking by law enforcement. As shorthand, this explainer refers to those measures as “mask bans.”7
These state and local efforts—which are now being tested in court—have prompted questions and commentary regarding states’ power to regulate federal actors.8 In particular, can state and local mask bans bind federal law enforcement without running afoul of the U.S. Constitution’s Supremacy Clause?9 This explainer begins in Part I by describing the recently enacted mask bans in California, Connecticut, New Jersey, Oregon, and Washington, and proposed laws elsewhere. Part II analyzes the constitutionality of these state efforts. It concludes that, under existing precedent, mask bans are neither clearly prohibited nor clearly permissible. Because the legal doctrine is murky, it is difficult to predict how legal challenges to mask bans might ultimately play out. While opponents can plausibly analogize mask bans to other state and local policies that courts have held cannot apply to federal actors, proponents can reasonably distinguish those precedents and analogize to cases upholding application of state and local policies to federal actors. Finally, Part III of the explainer provides an overview of other options states may have to address masking by federal law enforcement.
As of May 2026, lawmakers in at least thirty-three states have proposed or enacted legislation to prohibit law enforcement from masking, with varied levels of success.
In September 2025, California became the first state to enact a mask ban when Governor Newsom signed into law Senate Bill 627.10 The law makes it a crime (either an infraction or a misdemeanor) for law enforcement to “wear a facial covering that conceals or obscures their facial identity in the performance of their duties.”11 There are certain delineated exceptions to this rule: it does not apply to SWAT (Special Weapons and Tactics) team units, officers wearing medical masks to prevent the spread of disease or infection, or the use of masks to protect against “any toxin, gas, smoke, inclement weather, or any other hazardous or harmful environmental condition,” for example.12 Notably, the law applies to law enforcement officers at both the local and federal level, but exempts state officials.13
The law also requires law enforcement agencies to “maintain and publicly post a written policy regarding the use of facial coverings” that includes a “requirement that all sworn personnel do not use a facial covering when performing their duties” subject to a “list of narrowly tailored exemptions.”14 If a law enforcement agency complies, “[t]he criminal penalties” of the law do not apply to officers of that agency.15
California’s law was set to go into effect on January 1, 2026, but in November 2025 the federal government sued the state, seeking a court order that the ban was unconstitutional and the state could not enforce it against federal officials.16 That lawsuit is ongoing, and in February 2026 the district court granted the federal government’s motion for a preliminary injunction.17
Following California’s lead, New Jersey, Connecticut, Oregon, and Washington all enacted their own mask bans in spring 2026. New Jersey’s law generally prohibits law enforcement officers from wearing “a mask or disguise when interacting with the public while in the performance of the officer’s official duties.”18 It also requires law enforcement to provide identification before detaining or arresting an individual.19 Both requirements have enumerated exceptions.20 Connecticut’s law is similar.21 Oregon’s law, in addition to prohibiting masking, also requires law enforcement agencies operating in the state to (1) maintain and publicly post written policies on the use of facial coverings by law enforcement and (2) “ensure that, while on duty and actively engaged in official law enforcement activities, each law enforcement officer wears a uniform clearly and visibly displaying” the officer’s name or ID number and the agency name.22 Each of these provisions is subject to certain exceptions.23 Finally, Washington’s law prohibits masking, again subject to exceptions, and provides a civil cause of action for anyone “detained by a law enforcement officer in violation” of the law.24 As of the date of this publication, the federal government has sued New Jersey, seeking to invalidate its law, but not the other states.25 Lawmakers in Alaska,26 Arizona,27 Colorado,28 Florida,29 Georgia,30 Hawaii,31 Idaho,32 Illinois,33 Iowa,34 Kansas,35 Maryland,36 Massachusetts,37 Michigan,38 Minnesota,39 Mississippi,40 Missouri,41 Nebraska,42 New Mexico,43 New York,44 Ohio,45 Oklahoma,46 Pennsylvania,47 Rhode Island,48 Tennessee,49 Utah,50 Vermont,51 Virginia,52 and Wisconsin53 have introduced similar bills, with varying degrees of success. Senate Bill 352 in Virginia, for example, was recently passed by the Legislature and is waiting for the governor’s signature. If enacted, the law would make it a misdemeanor for a law enforcement officer to mask on the job.54 Mask ban proposals in Hawaii, Maryland, and Vermont have also been progressing in their state legislatures,55 while bills in other states have already failed.56
Some bills include civil penalties instead of or in addition to criminal ones. Pennsylvania’s bill, for example, would subject “federal immigration official[s] who” mask “to a civil penalty of $5,000 per violation.”57 Vermont’s would subject officers to a $1,000 fine or loss of “the officer’s professional licensure or certification, if applicable, or both.”58
In addition to these states, some localities have taken their own steps to prevent or discourage federal officials from concealing their identities through masks. In November 2025, Los Angeles County passed an ordinance prohibiting law enforcement from masking in the jurisdiction and requiring officers to wear visible identification.59 The ordinance went into effect in January 2026, but the Los Angeles County Sheriff’s Department has stated that it will not enforce the law against federal officials until the constitutionality of the state mask ban is decided in court.60 Lawmakers in St. Paul, Minnesota, and Milwaukee, Wisconsin have passed similar ordinances,61 while lawmakers in Denver, Colorado, and Portland, Oregon, have considered the same.62 Any local laws or ordinances that prohibit masking would generally be analyzed the same as state laws for purposes of Supremacy Clause immunities, so the considerations discussed in Part II apply equally to localities hoping to limit masking.63
It remains to be seen whether additional states or localities will pass their own mask bans. In the meantime, the DOJ’s challenge to California’s mask ban continues to play out in court, as discussed further in the next Part.64
Politicians and commentators have debated whether state mask bans comport with the Supremacy Clause of the U.S. Constitution.65 Under the Supremacy Clause, the federal government and its agents have certain protections from state law actions that would interfere with federal operations. Specifically, the doctrines of Supremacy Clause Immunity and Intergovernmental Immunity both pose potential hurdles for state mask bans.
Both doctrines stem from the Supremacy Clause and the basic idea that states cannot “interfer[e] with or control[] the operations of the Federal Government.”66 This “foundational” concept “traces its origin to McCulloch v. Maryland,”67in which Chief Justice John Marshall wrote that “the states have no power” to “retard, impede, burden, or in any manner control, the operations of the constitutional laws enacted by congress to carry into execution the powers vested in the general government.”68 At the same time, however, states have their own constitutionally grounded powers and interests, including interests in safeguarding the wellbeing of their residents and preventing federal overreach.69 The focus of the Supremacy Clause doctrines, then, “is the delicate balance between federal and state law enforcement powers.”70 “[T]he national government cannot be made to tolerate undue interference from the states in the enforcement of federal law.”71 “But neither should any state be made to tolerate unwarranted interference with its duty to protect the health and welfare of its citizens.”72
As the following sections explain, the constitutionality of applying mask bans to federal officers thus turns in large part on whether states’ attempts to protect their residents interfere with the execution of legitimate federal objectives. Under both Supremacy Clause Immunity and Intergovernmental Immunity, a central issue is whether preventing federal law enforcement from masking unduly interferes with the federal government’s operations.
With this central question in mind, the next parts of this section provide a brief overview of each type of immunity before analyzing how they might apply to state mask bans. Thoughtful commentators have reached different conclusions about the constitutionality of applying mask bans to federal actors, which underscores the unsettled nature of these questions.73 Based on the relevant precedents and likely arguments available to each side, this explainer concludes that mask ban proponents can reasonably defend their constitutionality, although it is by no means assured that they will prevail in court.
Many of the state mask bans discussed in Part I impose criminal penalties, and the doctrine of Supremacy Clause Immunity74 sets parameters for whether and when federal actors can be subject to state criminal prosecution.75 A separate explainer offers a deep dive into Supremacy Clause Immunity and discusses past instances in which states have sought to prosecute federal officers.76 Broadly speaking, Supremacy Clause Immunity, which derives from the Supremacy Clause (article VI, clause 2) of the U.S. Constitution, prohibits states from undermining federal law by criminally charging officials who are properly carrying out their lawful federal duties.77While the Supreme Court has not squarely addressed the contours of Supremacy Clause Immunity for more than a century,78 lower courts have generally used a two-part test to assess whether a federal actor is shielded from state criminal prosecution: (1) Was the official doing something authorized by federal law?, and (2) Were the official’s actions “necessary and proper” to fulfill their federal responsibilities?79 If the answer to either of these questions is no, the prosecution can move forward, although as scholars have noted, “[t]his test is much easier to recite than to apply.”80 By way of example, the U.S. Court of Appeals for the Fourth Circuit held that a marine who fatally hit a pedestrian after failing to yield to the right of way could be prosecuted for vehicular homicide under state law even though he was driving a military convoy.81 In contrast, a federal official who violates state speeding laws while pursuing a fleeing suspect is likely immune from prosecution where that violation was necessary to the performance of a federal duty, so long as he acts with reasonable care and prudence given the circumstances.82
Applying this framework here, whether a state can constitutionally enforce a mask ban against federal agents likely hinges on (1) whether the agents’ actions are authorized by federal law and (2) whether masking is necessary and proper to fulfill federal duties. The next subsections discuss each consideration in turn. Note that because Supremacy Clause Immunity applies only to state criminal prosecutions of federal officers,83 these questions are most likely to arise in criminal cases brought by a state against a federal officer.
When considering legal authorization, courts typically look to whether the federal officer’s conduct falls within the scope of the officer’s federal duties, rather than requiring explicit authority to perform the specific act in question.84 At least two commentators have suggested that because ICE agents mask on the job, masking falls within the general scope of their federal duties and is authorized.85 As these commentators point out, the question of federal authorization is often not seriously contested in litigation involving assertions of Supremacy Clause Immunity.86
That said, the Supreme Court has made clear that “an employee of the United States does not secure a general immunity from state law while acting in the course of his employment.”87In other words, the mere fact that an officer does something while on the job does not mean it is within the scope of his lawful duties.88“[T]he Supremacy Clause was not intended to be a shield for ‘anything goes’ conduct by federal law enforcement officers,”89 and officers cannot deliberately violate state laws to make their job “more convenient.”90
Where is the line drawn? “Courts determining whether a federal officer has acted within the scope of his federal authority” often “focus on the intent of the officer.”91 If the officer’s intent was to do his job, and he reasonably believes that federal law authorized his actions, he will likely meet this first element of the Supremacy Clause Immunity defense.
How does this play out in the masking context? There are colorable arguments on both sides. On one hand, there is no dispute that the Department of Homeland Security (DHS) is allowing its agents to wear masks, which may be enough to convince a court that such masking falls within the general scope of the agents’ duties. Former DHS Secretary Kristi Noem, for example, said at a press conference that DHS leaves it up to individual agents to decide whether they should mask.92 Todd Lyons, the acting director of ICE, similarly stated that, while masking is “not mandatory” for ICE agents, he would “allow” agents to keep masking if they chose to.93
Consistent with these statements, no federal law categorically prohibits agents from masking. Instead, in the aftermath of unidentified troops responding to protests during summer 2020, Congress amended the National Defense Authorization Act to require federal law enforcement to “visibly display” their identity and the name of the federal agency they serve when responding “to a civil disturbance.”94 While that law arguably bars masking in that specific circumstance, mask ban opponents could contend that it implicitly gives federal agents discretion to mask at other times.95
On the other hand, states can respond that a federal agency leadership’s apparent tolerance or “allowance” of mask-wearing does not qualify as an affirmative federal authorization, especially since other laws and regulations set a baseline expectation that officers will be identifiable. For example, DHS regulations, promulgated through the agency’s rulemaking authority, explicitly require ICE agents to identify themselves as immigration officers at the time of any arrest.96 There is no federal statute, nor officially enacted policy or promulgated rule, explicitly authorizing or requiring masking.97 In other words, masking is not an affirmative part of any federal duties, and it may instead be legally disfavored or prohibited in at least some contexts.
And then there is the issue of intent. The decision to mask appears to reflect a judgment by individual officers that concealment might help them minimize the risk of collateral consequences for their controversial work. While those concerns may inform the “necessary and proper” prong of the test, and are discussed more fully below, it is not clear that they alone establish that agents who mask “ha[ve] no motive other than to do [their] job.”98 Indeed, if a court were to focus on the intent of the officer,99 the court could well conclude that, rather than wearing a mask to fulfill their federal duties, agents are making that choice primarily out of “personal interest.”100 If that is true, or if a court were to find that the officers’ intent was for “any other reason” than to do their job,101 that may be fatal to a claim of federal authorization.102 Notably, while ruling on a different legal issue, a federal district court recently rejected the federal government’s asserted reasons for masking “as disingenuous, squalid and dishonorable” and wrote that “ICE goes masked for a single reason—to terrorize Americans into quiescence.”103
Even if a federal official’s actions are “authorized” by federal law, Supremacy Clause Immunity still would not apply unless a court determines that masking is “necessary and proper” for the officer to fulfill their federal responsibilities.
How do courts assess what is necessary and proper? Almost all lower courts have applied both a subjective and an objective analysis. For an act to be necessary and proper, then, the officer must have subjectively believed that it was necessary and proper to carry out his federal duties and that belief must be objectively reasonable.104 As detailed in a separate explainer,105 the analysis can be complex and contested, and different courts vary somewhat in their approaches. Against the backdrop of this uncertain doctrinal terrain, mask ban proponents can credibly contend that masking is neither necessary nor proper to the fulfillment of federal duties and that bans can thus be enforced against federal agents.
Federal law enforcement has defended the use of masks for two distinct but related reasons: (1) to protect against assaults and (2) to protect against doxxing (the public revealing of personal information such as home addresses or family member identities). Former DHS Secretary Noem, for example, claimed at a press conference that federal agents experienced a 1,000% increase in assaults during the summer of 2025.106 Accordingly, she said that DHS leaves it to individual agents to decide whether to wear a mask “to protect their identities from dangerous situations.” Similarly, in response to questions about masking in July 2025, acting ICE Director Lyons brought up the doxxing concerns and said that he would “allow” agents to keep masking if they chose to do so to “keep themselves and their family safe.”107
Proponents of mask bans can respond that, for several reasons, such assault and doxxing concerns do not make masking “necessary” to the performance of an officer’s federal duties. First, and perhaps most obviously, defenders of mask bans can argue that masking cannot be necessary to ICE operations because agents have—for decades—carried out their duties without wearing masks, and many continue to do so. As Dean Erwin Chemerinsky pointed out in his defense of California’s mask ban, “ICE agents have never before worn masks when apprehending people, and that never has posed a problem. Nor have other officers of local, state and federal law enforcement faced dangers from the public because they don’t wear masks in the streets.”108 Indeed, if the federal government thought that masking was necessary for ICE agents to perform their jobs, it could have made masking mandatory. Or it could have explicitly authorized such masking through a federal statute, regulation, or policy. It has not, which suggests that mask bans do not materially “interfere with federal policy and prerogatives.”109
Second, a closer look at the relevant data calls these proposed justifications into question. Although the federal government has not publicly released statistics regarding agent assaults,110 Fox News journalist Bill Melugin stated on the social media platform X that he reviewed the “underlying raw data” from DHS.111 That data purportedly showed a 690% increase in assaults—from 10 assaults between January 1 and June 30, 2024, to 79 assaults during the same period in 2025.112 While that is certainly an increase, the number of ICE agents in the field and the volume of immigration enforcement activities also rose significantly during that time.113 The assault figures, moreover, may reflect changes to how “assaults” are now defined and reported. Recently reported “assaults” have included “linking arms with a man” ICE is attempting to detain and asking to see their warrant,114 leaving garbage on an agent’s lawn, and creating a sign with profane language targeting an officer.115 In other words, it is not apparent that ICE agents conducting immigration enforcement activities today in fact face a meaningfully higher risk of assault than agents who conducted such activities in the past. Given that ICE now has over 20,000 “law enforcement and support personnel,”116 at least 6,500 of whom are deportation officers, and is actively growing,117 it is certainly debatable that a few dozen reported assaults make masking necessary,118 especially since it is not apparent how masking even reduces the likelihood of an assault.
Moreover, as Martin Kaste from NPR reported earlier this year, the government has not offered any public data that links assaults against officers “directly to doxing efforts.”119 And it is easy to imagine situations in which assaults are just as, if not more, likely to occur when agents wear masks. Targets of ICE enforcement, as well as observers of such enforcement activities, may well be more likely to resist both verbally and physically when agents’ identities are concealed.120
It is true, of course, that when officers are identifiable, it is easier for the public to figure out who they are and post identifying information online. The government, however, has not provided details on the extent to which ICE agents are in fact being subjected to doxxing. Many critics of masking have asserted that the proffered doxxing concern is merely pretext.121 And others have suggested that doxxing efforts may be increasing because agents are masking, which may lead some to see doxxing as the only way to seek accountability when officers violate the law.122 For example, two websites launched this summer “aimed at exposing federal immigration enforcement”—ICESpy.org and ICEList.is—were “created to restore transparency and accountability” in response to masked ICE agents “exacerbat[ing] panic and fear.”123 Particularly given the lack of public data on this issue, it is difficult to evaluate the government’s claims that concerns about doxxing make masking “necessary” for ICE officials to fulfill their lawful federal duties.
Proponents of state mask bans appear to accept that there are some situations in which it is indeed “necessary” for law enforcement officers to wear masks on the job, and the enacted and proposed mask bans include exceptions for such circumstances.124 SWAT Officers, for example, often must wear masks and face coverings to protect themselves from debris and chemical agents. Officers may also need to wear masks to protect against smoke or other toxins, or in inclement weather. In those cases, wearing the mask is directly necessary to their job in the sense that not masking would plainly hinder the performance of lawful duties. Proponents would distinguish these as special circumstances for necessity.
Building on their account of why masking is often not “necessary,” proponents of mask bans can also contend that it is not “proper.” First and foremost, they can make a strong case that masked law enforcement is antithetical to deeply rooted commitments to democracy and government transparency. With exceptions for undercover work, law enforcement agents at every level are generally expected to be identifiable when dealing with the public and making arrests.125 As the U.S. Supreme Court recognized in 1971 while discussing a federal statute that bars anyone from “go[ing] in disguise” for purpose of violating civil rights, those are the tactics of “private marauders,” not government officials.126 More recently, a federal district court observed that “[i]n all our history” as a country “we have never tolerated an armed masked secret police.”127 And as noted above, ICE agents specifically are required by law to identify themselves as immigration officers at the time of an arrest.128
Second, proponents can explain that masking by law enforcement can pose significant safety issues for both the general public and officers themselves that states may wish to minimize. When a masked individual in plain clothes approaches someone and tries to put them in an unmarked vehicle, there is no way for the public to know if it is a law enforcement operation or a kidnapping.129 Several commentators have written about how such interactions may place both parties at risk. The targeted individual may react with alarm—potentially through self-defense.130 Or armed bystanders may feel compelled “to intervene because they think it’s an illegal act happening.”131 Given that there have been multiple reported instances of individuals impersonating ICE agents and then kidnapping or otherwise assaulting victims,132 states may have strong arguments that masking is not only improper, but also actively harmful to public safety.
Finally, as they seek to establish that masking is neither necessary nor proper, proponents of mask bans may find at least some support in Fourth Amendment case law. While federal case law allows agents to be undercover and even conceal their identity in some circumstances, courts have also sometimes identified masking as one factor that can make law enforcement searches and seizures “unreasonable” and thus unconstitutional.133 Indeed, if masking is at least sometimes disfavored as a Fourth Amendment matter, that would seem not only to raise doubts about its necessity and propriety, but also about whether it should be treated as legally authorized, at least absent express federal statutory or regulatory approval (which, as discussed in the prior subsection, does not currently exist).134
Ultimately, much of the Supremacy Clause Immunity analysis will turn on exactly how the court frames the doctrinal inquiry and the level of granularity it applies when assessing whether masking is both legally authorized and necessary and proper. Mask ban proponents can reasonably contend that masking itself is neither authorized by federal law nor necessary or proper for the performance of official duties, but without additional guidance from the Supreme Court, lower courts could well diverge on these questions.
A second form of immunity, which the federal government has already invoked to neutralize state mask bans, is Intergovernmental Immunity, also rooted in the U.S. Constitution’s Supremacy Clause.135 The doctrine bars state and local laws that “either regulate the United States directly or discriminate against the Federal Government or those with whom it deals.”136
Although there is substantially more legal authority on Intergovernmental Immunity than Supremacy Clause Immunity, there remain unanswered questions about how the doctrine applies specifically to mask bans. Only one court to date has grappled with the question. In response to California’s mask ban, the federal government sued the state, seeking to invalidate the law under Intergovernmental Immunity. The government sought a preliminary injunction prohibiting California from enforcing the mask ban against federal officials.137 The government argued that the mask ban failed under both prongs of the Intergovernmental Immunity analysis: it directly regulated the federal government and discriminated against it. But the U.S. District Court for the Central District of California disagreed on the first prong. As explained in further detail below, the court held that California’s mask ban did not directly regulate the federal government. However, because the ban applied to federal law enforcement officers but not similarly situated state officers, the court found that the law discriminated against the United States and granted the federal government’s request for a preliminary injunction.138
It is not yet clear how other courts will approach this issue. As with Supremacy Clause Immunity, much will turn on how a court conceptualizes the role of masking in undertaking the federal law enforcement functions. But proponents have several arguments that well-drafted mask bans apply neutrally and fall sufficiently far from the heartland of the federal function so as not to violate the Supremacy Clause.
Do state mask bans directly regulate the federal government? The litigation surrounding California’s mask ban demonstrates the unsettled nature of this question.
In September 2025, California enacted two state laws: the No Secret Police Act (the mask ban discussed in Part I) and the No Vigilantes Act. The No Vigilantes Act requires any non-uniformed law enforcement officer operating in California to “visibly display identification that includes their agency” and their name and/or badge number, subject to certain exceptions. Failure to do so is punishable as a misdemeanor. It also requires all law enforcement agencies operating in California to “maintain and publicly post a written policy on the visible identification of sworn personnel.” The law applies to law enforcement at all levels—local, state, and federal.139
In November 2025, the federal government challenged both laws, arguing that both were unconstitutional direct regulations because they “constrain[] the conduct of federal agents and employees” in the scope of their federal employment.140 As an example, the federal government pointed to a 2010 Ninth Circuit case in which the court struck down two city ordinances that prohibited federal military recruiters from recruiting or attempting to recruit minors in California on the grounds that the state was directly interfering with how federal actors performed their federal function.141 The federal government asserted that California’s mask ban and identification requirements similarly constrained federal officer behavior. Several legal commentators, including Professors Noah Chauvin and Vikram Amar, have also offered arguments along these lines.142
The U.S. District Court for the Central District of California—the first court to address this specific issue—disagreed with the government’s arguments. In its order on the government’s motion for a preliminary injunction, the court explained that not every state law constraint on federal agents violates Intergovernmental Immunity. The court cited the canonical (albeit somewhat cryptic) Supreme Court case addressing the direct regulation standard: Johnson v. Maryland.143
In Johnson, a federal Post Office employee was convicted under Maryland law of driving a vehicle without a state-issued driver’s license.144 The Supreme Court overturned the conviction under the Supremacy Clause. The Court observed that “an employee of the United States” is not generally immune “from state law while acting in the course of his employment,” while simultaneously explaining that “even the most unquestionable and most universally applicable of state laws . . . will not be allowed to control the conduct of [an agent] of the United States acting under and in pursuance of the laws of the United States.”145 Specifically, the Court indicated that where “the United States has not spoken,” state law can validly apply, even if it “affect[s] incidentally the mode of carrying out the [federal] employment—as, for instance, a statute or ordinance regulating the mode of turning at the corners of streets.”146 In contrast, the Supremacy Clause forbids a state from “requir[ing] that [federal officials] desist from performance until they satisfy a state officer upon examination that they are competent for a necessary part of [their federal duties] and pay a fee.”147 The Supreme Court concluded that Maryland’s driver license requirement did “not merely touch the Government servants remotely by a general rule of conduct” but “la[id] hold of them in their specific attempt to obey orders and require[d] qualifications in addition to those that the Government ha[d] pronounced sufficient.”148 It was therefore unconstitutional.
Under Johnson, then, one way to think about whether mask bans or other state laws regulate the federal government directly is to ask whether they are like traffic laws that “affect incidentally the mode of carrying out [federal agents’] employment” or whether they are more akin to a driver’s license requirement that “lays hold of [officials] in their specific attempt to obey orders” or requires that they “desist from performance until they satisfy a state” requirement.149 In its analysis of California’s mask ban and identification requirement, the district court applied a “functional approach,” inquiring into “whether the regulations at issue interfere with or control the operations of the Federal Government.”150 Under this approach, the court found the laws to be “analogous to traffic laws that, in a similar sense, dictate how a federal officer may operate a vehicle on state roads but are nonetheless enforceable against federal officers, subject to immunities.”151
The court made this determination because it found that the federal government had “not shown that its current practices with respect to masking and identification are essential to federal law enforcement operations.”152 “Security concerns” such as doxxing, harassment, and assault “exist for federal law enforcement officers with and without masks.”153 But, the court explained, “these harms are the result of criminal behavior. A rule that prohibits law enforcement officers from wearing masks or requires them to have visible identification does not facilitate or enable criminals to harm law enforcement officers.”154 Indeed, the court found “that the presence of masked and unidentifiable individuals, including law enforcement, is more likely to heighten the sense of insecurity” and make situations more dangerous for everyone involved.155
Additionally, the court noted that “the historical tradition of law enforcement officers not masking their identities and the current practice of some federal officers who choose to expose their identity alongside colleagues with masks” undermined the DOJ’s argument that masking or concealing one’s identity is necessary for federal law enforcement.156 Based on its analysis, the district court concluded that the United States was not likely to succeed on the merits of its complaint that the mask ban or identification requirement directly regulated the federal government in violation of the Intergovernmental Immunity doctrine. However, as explained in depth below, the court only denied the government’s request for a preliminary injunction as to the identification requirement, after finding that the mask ban was unconstitutional under the discrimination prong.
The federal government appealed the denial of the preliminary injunction of the No Vigilantes Act (the identification requirement) to the U.S. Court of Appeals for the Ninth Circuit. On April 22, 2026, the Ninth Circuit held that, contrary to the district court’s conclusion, the No Vigilantes Act did directly regulate the federal government and was therefore likely unconstitutional. The Court thus granted the United States’ motion for an injunction pending appeal.157
The court began by defining a “direct regulation” under the Intergovernmental Immunity analysis as “one that ‘lays hold of’ federal officers ‘in their specific attempt to obey orders and requires qualifications in addition to those that the federal Government has pronounced sufficient.”158 A direct regulation, the court explained, “imposes conditions upon a function of government, and regulates the right to carry on the business of the federal government.”159
The panel concluded that the No Vigilantes Act constituted “direct regulation,” regardless of its impact on federal operations, because it “directly regulate[d] conduct reserved to sovereigns.”160 The panel distinguished the example of traffic laws applying to federal workers—which the Supreme Court has said are valid—on the ground that traffic laws “regulat[e] conduct that any ordinary citizen could perform,” whereas California’s prohibition on concealing one’s identity “applie[d] exclusively to law enforcement agencies and their officers, including federal law enforcement agencies and federal law enforcement officers.”161 Because the regulation applied to “the federal government qua government,”162 the panel concluded that it was “void irrespective of whether the regulated activities are essential to federal functions or operations, and irrespective of the degree to which the state law interferes with federal functions or operations.”163
Although the panel was only analyzing the identification requirement, not the mask ban, its decision complicates any analysis of mask bans under the direct regulation prong. The federal government has already cited to the decision in its efforts to invalidate other state mask bans.164 But there are some strong arguments available to states that well-crafted mask bans can be constitutionally applied to federal law enforcement, the Ninth Circuit decision notwithstanding.
As an initial matter, there are differences between state mask bans and state laws requiring officers to affirmatively display identification that may matter to a court’s analysis, even under the Ninth Circuit’s test. For instance, identification requirements necessarily require the law enforcement agency to procure and issue identification badges to agents in accordance with state law. Mask bans, on the other hand, do not affect the agency in the same way, instead simply prohibiting individual officers from masking on the job. Additionally, there is no federal rule or policy requiring or even allowing masking, meaning the analysis of a state mask ban may differ from a state law regulating agents’ display of identification. Finally, mask bans only affect the subset of individuals who choose to mask, rather than all federal agents. In that way, any mask bans may be distinguishable as general regulations that happen to affect some federal officers, rather than a direct regulation of the federal government.
Additionally, it is far from clear whether other circuits will apply the same legal test as the Ninth Circuit panel. As noted above, the panel reasoned that the provision “directly regulated” the federal government because it targeted “conduct reserved to sovereigns”—law enforcement activity—as opposed to “conduct that any ordinary citizen could perform”—like driving.165 Other circuits, however, have not described or applied the doctrine in these formalistic terms. Instead, they have focused on whether the regulation truly “controls” a federal function by subjecting it to state whims—or, in the words of the Supreme Court, whether a policy “make[s] it unlawful to carry out the duties of a federal office without local permission”166—versus incidentally burdening federal activity.
The Fifth Circuit, for example, has explained that “the key question” for any Intergovernmental Immunity direct regulation challenge is whether “state law seeks to improperly ‘control’ the employee’s federal duties,” on the one hand, or “whether the law only ‘might affect incidentally the mode of carrying out the employment,’” on the other.167 The Third Circuit, similarly, has emphasized that “[i]ntergovernmental immunity is not a formalist doctrine” and embraced a “functional, effects-based test” to a recent direct regulation challenge.168
Under an approach that emphasizes the same “anti-interference throughline”169 as the Third and Fifth Circuit decisions, states have arguments that especially where, as here, there is no federal requirement to mask, state laws that allow masking under only certain conditions fail to “impose a burden on the federal government in a way the intergovernmental immunity doctrine considers problematic.”170 Instead, they are arguably more akin to the kind of generally applicable state law that the Supreme Court has held can apply to federal officials, even if it “affect[s] incidentally the mode of carrying out the [federal] employment—as, for instance, a statute or ordinance regulating the mode of turning at the corners of streets.”171
Indeed, the Ninth Circuit’s decision does not fully explain its conclusion that the No Vigilantes Act “seeks to control [federal officials’] conduct in performing law enforcement operations;” “purports to override the federal government’s power to determine whether, how, and when to publicly identify its officers;” and “in so doing, it aims to regulate the manner and conditions under which federal agents can enforce federal law.”172 One of the case’s disputes centered on whether, or how, federal law speaks to identification requirements in the first place—or, put differently, whether these requirements truly affect officers’ conduct in their official, authorized capacity. But as noted above, especially given that federal leadership appears to have disclaimed any affirmative masking directive, instead leaving any decision to mask to individual officers, it is not clear that even under the Ninth Circuit panel’s test, a mask ban would “control” federal officials in the same way as the No Vigilantes Act.
To be sure, other courts could conclude, similar to the Ninth Circuit’s analysis, that a state policy dictating when federal officials may conceal their identities “directly” regulates how they perform a federal function, similar to the driver’s license requirement in Johnson. Depending on the jurisdiction, though, states can credibly attempt to analogize mask bans to traffic or other laws that only “affect incidentally the mode of carrying out” federal immigration enforcement. As described above in Section II.A, no federal statute or regulation expressly addresses masking in these circumstances, which suggests that this is a matter on which “the United States has not spoken,” and that mask bans do not impede any “attempt to obey orders.”173 Likewise, states are not attempting here to determine whether federal actors are “competent” to perform their duties, and there are also strong arguments, discussed above, that masking is neither necessary nor proper for achieving the bona fide objectives of federal immigration enforcement.174
In addition to the California decision, a recent Fifth Circuit decision provides a useful example for thinking through the direct regulation prong of the Intergovernmental Immunity analysis. Last year the Fifth Circuit denied the federal government’s invocation of Intergovernmental Immunity when Texas brought common-law conversion and trespass claims against federal Border Patrol agents.175 The agents had cut a concertina wire fence that the State had placed along part of its border with Mexico. The federal government argued that removing the wire was “sometimes necessary to fulfill [the Border Patrol’s] statutory duty of ‘patrolling the border to prevent the illegal entry of aliens into the United States,’”176 and that Texas’s lawsuit was thus invalid under Intergovernmental Immunity because it sought to “directly regulate the federal government’s operations.”177
The Fifth Circuit disagreed. The court explained that “the key question” on the regulation prong “is whether state law seeks to improperly ‘control’ the employee’s federal duties, or whether the law only ‘might affect incidentally the mode of carrying out the employment.’”178 Even though Texas’s suit impacted how the federal agents carried out their duties, and even though it “impose[d] a burden on agents,” Intergovernmental Immunity was not implicated because the impact and burden were only incidental to achieving the federal policy.179
Such reasoning could apply to state mask bans as well. Proponents of these laws may cast them as laws only “incidentally” affecting “the mode of carrying out” an agent’s duties without “prohibit[ing] the federal government from enforcing immigration law,” or otherwise interfering with authorized federal duties.180
Overall, it is difficult to predict how other courts might evaluate these arguments. There are compelling precedents that could be argued to support both sides. The federal government will no doubt continue to argue vigorously that any attempt to enforce a state mask ban against federal agents amounts to impermissible direct regulation of federal affairs in violation of Intergovernmental Immunity. But, depending on the specifics of the mask bans at issue, states may be able to counter with arguments and precedents that their laws do not directly regulate federal actors in ways the doctrine forbids.
On the second prong of the Intergovernmental Immunity analysis—whether the state law discriminates against the federal government—there are again persuasive arguments on both sides, depending on the specifics of the law at issue.
As a threshold matter, any mask ban that applied only to federal law enforcement officers would almost certainly be unconstitutional under this prong.181 State governments cannot single out federal agents for differential treatment without running afoul of Intergovernmental Immunity. The U.S. District Court for the Central District of California’s recent ruling on California’s mask ban illustrates this proposition. Although the court found that the mask ban did not directly regulate federal officers, as discussed above, the district court nonetheless granted the government’s request for a preliminary injunction.182 California’s mask ban applies to law enforcement at the local and federal level, as well as law enforcement from other states, but does not apply to “similarly situated” California “state law enforcement officers.”183 As such, the district court found that the federal government was likely to succeed on the merits of its claim that the mask ban unlawfully discriminated against the federal government in violation of the Intergovernmental Immunity doctrine.184 After the court’s ruling, Democratic lawmakers in California introduced a bill to amend the mask ban to apply to state officials, but it has not been enacted.185
Despite the carve out in California’s law, many of the proposed mask bans discussed previously in Part I apply to law enforcement officers at all levels of government—local, state, and federal. So, at least on their face, they do not overtly discriminate against the federal government. But even absent overt discrimination, mask bans may still fail under this prong. From the federal government’s perspective, mask bans are targeting and discriminating against federal agents because they aim to hamper ICE’s current ways of operating. Statements from some state officials seem to acknowledge such motivations.186 Governor Newsom’s press release on California’s mask bans, for example, states that the law is part of the state’s efforts “to protect residents from tactics being employed by President Trump and Stephen Miller’s secret police.”187
At least some courts, however, have disclaimed the relevance of such statements, explaining that “the intergovernmental immunity analysis is not concerned with the potential ‘nefarious motive’ behind the challenged law.”188 Instead, some courts focus on the text of the law and its practical effects. Proponents of mask bans thus have a strong argument that facially neutral laws that apply to all levels of law enforcement survive the Intergovernmental Immunity challenge. As the Supreme Court has written, “the State does not discriminate against the Federal Government and those with whom it deals unless it treats someone else better than it treats them.”189
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In many respects, the central inquiry under both the Supremacy Clause Immunity and Intergovernmental Immunity doctrines discussed above will look similar and turn on similar arguments. At the core of both doctrines is the central question discussed at the beginning of this part: Do state laws that limit masking by law enforcement interfere with the federal government’s operations in a way that offends the Supremacy Clause? While mask ban opponents will insist that they do, proponents have credible and potentially persuasive arguments that states in our federalist system may constitutionally apply these laws to federal agents.
Whether or not state mask bans are ultimately upheld in court, they are not the only tool at states’ disposal for limiting or discouraging law enforcement masking. There are several other approaches states can take.
First, states can potentially incorporate anti-masking provisions into civil laws that impose liability for intentional state torts. The Federal Tort Claims Act (FTCA) contains a proviso waiving federal sovereign immunity for claims of assault, battery, false imprisonment, false arrest, abuse of process, or malicious prosecution against any federal investigative or law enforcement officer.190 In other words, through the mechanisms of the FTCA, individuals may bring claims against federal law enforcement agents for those specific torts. States may seek to make these tort claims more powerful by providing for additional liability when the tort is committed by an officer wearing a mask. For example, California’s mask ban includes a provision that “any person who is found to have committed an assault, battery, false imprisonment, false arrest, abuse of process, or malicious prosecution, while wearing a facial covering in a knowing and willful violation of this section shall not be entitled to assert any privilege or immunity for their tortious conduct against a claim of civil liability, and shall be liable to that individual for the greater of actual damages or statutory damages of not less than ten thousand dollars, whichever is greater.”191 The application of this provision has not been tested in courts, but on its face it discourages mask wearing by subjecting federal officers to increased state tort liability for torts committed while masked. Long-term, this legal change could curb mask wearing in states that adopt it.
Second, at least one commentator has suggested that states or localities could affirmatively authorize or even require their law enforcement officers to “verify[] the identity of purported ICE agents operating in their jurisdictions.”192 Even without such direct authorization, officers can likely request such verification as part of their ordinary duties. Given the rise of “high-profile crimes committed by individuals impersonating police officers and ICE agents, state and local police are under no obligation to take it on faith that masked men seizing people off of the streets have lawful authority to do so.”193 For example, the No Vigilantes Act in California would authorize state officers to “request an alleged law enforcement officer to present identification when there is probable cause or reasonable suspicion to believe the alleged law enforcement officer has committed a crime, including, but not limited to, impersonating a peace officer.”194
Third, state and local governments can take various measures designed to encourage federal agents to unmask. For example, states and localities are “in a strong position to negotiate with ICE over how the federal agency conducts operations within their jurisdiction” because they “have access to significant resources—including internal databases, local knowledge, and manpower—that ICE often lacks.”195States or localities could withhold cooperation with ICE unless and until it changes its operational policies, including on masking. And at least one commentator has suggested that, if state or local governments made it a priority to “apprehend and prosecute those perpetrating crimes targeting ICE,” agents may be less likely to mask.196
Fourth, state courts can take action to prohibit masking in their facilities. For example, in September 2025, Connecticut Supreme Court Chief Justice Raheem Mullins issued a new policy that prohibits law enforcement agents from wearing face coverings in court facilities unless they have a medical need or prior approval from the judiciary.197
Finally, many states and some localities have existing mask bans that are generally applicable to the public that could potentially be used against federal officials in some ways.198 For example, Florida has laws, which were originally aimed at the Ku Klux Klan, that prohibit people above the age of 16 from wearing a mask, hood, or other facial disguise in specified places when the wearer intends to interfere with the exercise of a person’s legal rights, to deprive any person of equal protection, or “intimidate, threaten, abuse, or harass.”199 Other states could consider passing similar mask bans that apply more generally—such as mask bans that apply to anyone purporting to be a law enforcement officer.
Could such mask bans be used to prosecute masked federal agents? Maybe.200 If the law’s predicates are met (e.g., that the perpetrator acted “with the intent to intimidate, threaten, abuse, or harass” or to violate someone’s civil rights), agents could have difficulty invoking the protections of either Supremacy Clause Immunity or Intergovernmental Immunity. And such generally applicable mask bans—general rules that regulate “conduct that any ordinary citizen could perform,”—would avoid the Ninth Circuit panel’s concern with state laws that “regulate[] the government qua government.”201 These laws may thus allow state officials to prosecute masked federal law enforcement in at least some circumstances without having to enact new legislation, or without enacting legislation that applies solely to law enforcement.
Courts and commentators have long pondered and debated the question of when and how state and local governments can regulate federal officers. Current state efforts to prohibit law enforcement from masking while performing their official duties highlight unanswered questions in the Supremacy Clause and Intergovernmental Immunity doctrines. How should courts determine what actions are “authorized” by federal law? When is something necessary and proper to the fulfillment of federal duties? Where is the line between state laws that incidentally burden the federal government and those that directly regulate it? These are the questions that will be sorted out in court. While existing doctrine gives opponents of these laws ample grounds to challenge them, it also offers proponents a variety of cogent defenses.