Even before the 2024 presidential election, Donald Trump threatened to invoke the Insurrection Act to deploy the U.S. military domestically to quell protests, fight crime in so-called “crime dens” like New York City and Chicago, and police the border. Once president, in the summer and fall of 2025, Trump relied on a different authority, 10 U.S.C. § 12406, to federalize National Guard troops and send them into Los Angeles, Portland, and Chicago, ostensibly to protect federal immigration officers and federal property during protests against ICE surges in those cities. And in May 2026, he said he would not rule out sending the National Guard to voting locations in November.
Although the U.S. Supreme Court ruled against Trump’s use of § 12406(3) in Trump v. Illinois, the case did not resolve many open questions about deployments of the U.S. military and National Guard forces domestically. This blueprint provides an overview of the legal framework that governs the domestic use of the military, the critical questions that this framework leaves unresolved, and a set of proposed reforms to provide clarity and accountability.
The Problem: Outdated and Overlapping Laws Invite Abuse
The authorities related to domestic deployments of the U.S. military are outdated, vague, subject to abuse, and have been in need of reform for a number of years. But until now, the urgency to do so has not been present. Almost all invocations of the Insurrection Act have been at the request of a state’s governor, with the exception of a handful of instances during the post-Brown v. Board of Education era, when it was used to enforce desegregation and civil rights laws. The last invocation was in 1992, in response to the Los Angeles riots spurred by the acquittal of police officers after the brutal beating of Rodney King. But with the repeated threats to invoke the Act, and the federalization and deployment of National Guard forces under a separate statutory authority in 2025, it has become increasingly important to seek more clarity than existing law provides about when the U.S. military can lawfully be used domestically, what sorts of activities they can engage in domestically, and what judicial review is permissible.
The Legal Framework
1.The Constitution
The U.S. Constitution divides the power over the military between Congress and the president. Congress has the power under Article I “to provide for the organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States,” art. I, sec. 8, cl. 16; and “to provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions,” art. I, sec. 8, cl. 15. Under Article II, the president is the “Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States.” art. II, sec. 2.
Congress has exercised its authority to provide for the organizing of the “militia” through a series of Militia Acts beginning in 1792. These first authorized the states to form their own militias, reporting to their governors, and authorized the president to call forth the state militias as necessary to repel invasion or suppress insurrection. Subsequent legislation created the National Guard system—the modern equivalent of the state militias that could be called forth in certain circumstances by the president.
2. The Posse Comitatus Act – A Key Statutory Constraint on Use of the Military to Execute the Laws Domestically
The Posse Comitatus Act (PCA), 18 U.S.C. § 1385, provides the most significant statutory constraint on the use of the military domestically. The PCA is a criminal statute that bars the use of the U.S. military (except for the Coast Guard) and federalized National Guard units “to execute the laws” domestically, absent “express authoriz[ation] by the Constitution or Act of Congress.” The PCA was passed at the end of Reconstruction in 1878 with the intent on the part of its southern congressional supporters of preventing the use of federal troops to safeguard civil rights and protect Black voters in formerly Confederate states.
Despite its history, the PCA is consistent with the fundamental principle embedded in the Constitution that the military should not engage in domestic law enforcement. As the Supreme Court said in Laird v. Tatum, there is “a traditional and strong resistance of Americans to any military intrusion into civilian affairs,” that “has deep roots in our history and found early expression, for example, in the Third Amendment’s explicit prohibition against quartering soldiers in private homes without consent and in the constitutional provisions for civilian control of the military.”
There are no express constitutional exceptions to the PCA. However, the Department of Defense and Department of Justice have taken the position that there is inherent constitutional authority for the president to use the military domestically in two circumstances: 1) in emergencies to prevent loss of life, wanton destruction of property, and to restore government functioning and public order; and 2) to protect federal property and federal functions. Trump relied on the second exception, known as the protective power, to order the deployment of U.S. Marines to protect federal immigration officials and federal property in Los Angeles during protests against ICE activity in the summer of 2025. (This deployment of active-duty U.S. military members was in addition to the federalization and deployment of the California National Guard under 10 U.S.C. § 12406.)
3. The National Guard and “Hybrid” (federal missions under state control) Title 32 Authorities
Before turning to the most common statutory exception to the PCA – the Insurrection Act – it’s helpful to understand the statutory mechanisms for domestic deployments of the National Guard. The National Guard can operate domestically in three different statuses:
- State active-duty status – the governor can deploy the state National Guard consistent with state law and paid for by the state;
- “Hybrid” status under Title 32 – the governor can deploy the National Guard for federal missions paid for by the federal government, but the Guard remains under the control of the governor;
- Federalized under Title 10 – the president can federalize the National Guard pursuant to statutory authority, such as the Insurrection Act, 10 U.S.C § 251, et. seq., or 10 U.S.C. § 12406.
Importantly, the PCA only applies to the National Guard when it is federalized, unless the federalization is pursuant to an exception such as the Insurrection Act. When in state active-duty or hybrid Title 32 status, the National Guard is not “federalized,” so it is not subject to the PCA.
So what can the National Guard be used to do in this hybrid status? Under Title 32, section 502, National Guard units can be required to participate in training, drilling, and instruction. Section 502(f) also allows for National Guard members to be ordered to perform “other duty” with or without the member’s consent. “Other duty” under § 502(f) has been relied on by presidents of both parties to use the National Guard for support operations and missions such as airport security after 9/11, disaster relief, and border operations. It is understood that the consent of the governor is required for these missions under § 502(f), and indeed, it is not uncommon for governors to request that their units be deployed in Title 32 status after natural disasters or in other emergencies because the federal government foots the bill.
Section 502(f) was controversially used in the summer of 2020 to deploy National Guard troops from Washington, D.C., and several states into the capital city in response to Black Lives Matter protests. Although it was unclear at first what the authority was for the deployment, in a subsequent letter from then-Attorney General William Barr to D.C. Mayor Muriel Bowser, he explained that the Guard had been deployed pursuant to § 502(f). And although Bowser had objected to the deployment, she was powerless to stop it because the District of Columbia is not a state and its National Guard reports to the secretary of the Army and up the chain of command to the president, rather than to a governor. The governors who sent their National Guards to the city did so voluntarily, while others refused and did not send their units.
The Trump administration has not attempted to force a governor to deploy its National Guard under § 502(f), although it did ask the governors of Oregon and Illinois to deploy under § 502(f) in 2025 before federalizing their Guard units under 10 U.S.C. § 12406 when they declined, as described below.
4. The Insurrection Act – An Exception to the Posse Comitatus Act
The most common statutory exception to the PCA is the Insurrection Act, a series of laws dating to 1792 and last substantively amended in 1871 as part of the Ku Klux Klan Act. It provides for both the federalization and domestic deployment of the National Guard, referred to as “the militia” of a state, and domestic deployment of the regular military, referred to as “the armed forces,” when certain predicate conditions are met. Its key provisions are codified at sections 251-253 of Title 10 of the U.S. Code:
§ 251: Whenever there is an insurrection in any State against its government, the President may, upon the request of its legislature or of its governor if the legislature cannot be convened, call into Federal service such of the militia of the other States, in the number requested by that State, and use such of the armed forces, as he considers necessary to suppress the insurrection.
§ 252: Whenever the President considers that unlawful obstructions, combinations, or assemblages, or rebellion against the authority of the United States, make it impracticable to enforce the laws of the United States in any State by the ordinary course of judicial proceedings, he may call into Federal service such of the militia of any State, and use such of the armed forces, as he considers necessary to enforce those laws or to suppress the rebellion.
§ 253: The President, by using the militia or the armed forces, or both, or by any other means, shall take such measures as he considers necessary to suppress, in a State, any insurrection, domestic violence, unlawful combination, or conspiracy, if it–
(1) so hinders the execution of the laws of that State, and of the United States within the State, that any part or class of its people is deprived of a right, privilege, immunity, or protection named in the Constitution and secured by law, and the constituted authorities of that State are unable, fail, or refuse to protect that right, privilege, or immunity, or to give that protection; or
(2) opposes or obstructs the execution of the laws of the United States or impedes the course of justice under those laws.
In any situation covered by clause (1), the State shall be considered to have denied the equal protection of the laws secured by the Constitution.
Thus far, Trump has not invoked the Insurrection Act to deploy the U.S. military or to federalize and deploy the National Guard domestically.
5. 10 U.S.C. § 12406 – Another Statutory Source for Federalization of National Guard Units
The statute at the center of the 2025 National Guard controversies and related litigation is not the Insurrection Act but a less familiar provision, Section 12406 of Title 10 of the U.S. Code. It provides:
Whenever-
(1) the United States, or any of the Commonwealths or possessions, is invaded or is in danger of invasion by a foreign nation;
(2) there is a rebellion or danger of a rebellion against the authority of the Government of the United States; or
(3) the President is unable with the regular forces to execute the laws of the United States
the President may call into Federal service members and units of the National Guard of any State in such numbers as he considers necessary to repel the invasion, suppress the rebellion, or execute those laws. Orders for these purposes shall be issued through the governors of the States or, in the case of the District of Columbia, through the commanding general of the National Guard of the District of Columbia.
Trump relied on § 12406(2) and (3) to federalize and deploy National Guard units to Los Angeles, Portland, and Chicago in 2025 in response to protests against ICE surges in those cities. In Portland and Chicago, the Trump administration first asked the governors of Oregon and Illinois to deploy their own state National Guard units in hybrid status under Title 32, § 502(f), and threatened that if they did not agree within a certain number of hours, the National Guards would be federalized. Neither governor agreed, and the administration relied on § 12406 to federalize them.
All three federalizations and deployments were challenged in federal courts. The states argued that the predicates for federalization and deployment were not met because the protest activity against ICE was not equal to a “rebellion” or “danger of rebellion” against the authority of the government of the United States and because state and local law enforcement were able to police the protest activity and any violence associated with it so that ICE remained able to enforce federal law.
In all three states, the district courts agreed with the states that the predicates for federalization were not met and enjoined the National Guard deployments. The United States sought stays of all three injunctions in the federal courts of appeals (the Ninth Circuit for California and Oregon and the Seventh Circuit for Illinois). The Ninth Circuit granted the stays. The Seventh Circuit denied the stay as to the injunction barring deployment (but allowed the continued federalization), and the United States sought emergency review in the Supreme Court in Trump v. Illinois.
Although the United States argued that “regular forces” for purposes of § 12406(3) meant civilian law enforcement, the Supreme Court concluded that the term “regular forces” in § 12406(3) “likely refers to the regular forces of the United States military.” Thus, it held that before calling forth the National Guard under § 12406(3), the president must be “‘unable’ with the regular military ‘to execute the laws of the United States.’” And further, that this would require “statutory or constitutional authority to execute the laws with the regular military.”
The Court pointed out that the United States had not invoked a statute that provided an exception to the Posse Comitatus Act that would allow the military to execute the laws in Illinois. And although the United States relied on what it termed the president’s “inherent constitutional authority” to use the military “to protect federal personnel and property,” the Court noted that this was inconsistent with the longstanding view of the Executive Branch that “performing such protective functions does not constitute ‘execut[ing] the laws’ within the meaning of the Posse Comitatus Act.” Thus, the Court found it “hard to see how performing those functions could constitute ‘execut[ing] the laws’ under § 12406(3)” and concluded that “at least in this posture, the [United States] has not carried its burden to show that § 12406(3) permits the President to federalize the Guard in the exercise of inherent authority to protect federal personnel and property in Illinois.”
The Goal: Clear Rules
Despite significant litigation in 2025 over the president’s use of § 12406 to federalize and deploy the National Guard in three states, including evidentiary hearings and a full trial on the merits, the American public is left with little additional clarity about the legal authorities for using the military domestically than it had at the beginning of the Trump administration. It thus behooves the public to seek answers to some of the unanswered questions raised by the litigation and by other threats of domestic use of the military. Without more clarity, the potential for abuse abounds, including the very thing the founders wanted to avoid: military stationed among the people, acting “as a force of uniformed peace-keepers, or policemen.”
Among other issues, the following questions remain:
1. Are the president’s findings of the predicates for federalization and deployment under § 12406 or the Insurrection Act judicially reviewable?
The United States argued in each case brought in 2025 that the president’s orders were unreviewable. In Trump v. Illinois, the Supreme Court expressly declined to “address the reviewability of findings made by the president under § 12406(3) or any other statute.” Each of the lower courts had rejected the U.S. government’s argument that the president’s findings are unreviewable.
Historical deference to the president’s determinations under the Insurrection Act dates to the Supreme Court’s 1827 case, Martin v. Mott. There, the Court held that, with respect to the president’s authority to call forth the militia to repel an invasion under the 1795 precursor to the Insurrection Act, “the authority to decide whether the exigency has arisen, belongs exclusively to the President,” such that “his decision is conclusive upon all other persons.”
Despite the breadth of this language, judicial review was not at issue in that case. Instead, it was whether a militiaman who was court-martialed, convicted, and fined for refusing to report when ordered into federal service by President James Madison during the War of 1812 could challenge the taking of his mule in lieu of a fine because the order was invalid. Justice Joseph Story, writing for the majority, and noting the limited power of the president to call the militia into service, said
If it be a limited power, the question arises, by whom is the exigency to be judged of and decided? Is the President the sole and exclusive judge whether the exigency has arisen, or is it to be considered as an open question, upon which every officer to whom the orders of the President are addressed, may decide for himself, and equally open to be contested by every militia-man who shall refuse to obey the orders of the President.
It was only after this explanatory context that Justice Story wrote, “We are all of the opinion, that the authority to decide whether the exigency has arisen, belongs exclusively to the President.” That means this case, though important for the question it did address as to individual militia members, does not establish the availability (or not) of judicial review of the president’s determination of the predicates for invocation of the Insurrection Act or other statutory sources for domestic deployments.
A century later, in Sterling v. Constantin, the Supreme Court reviewed the Texas governor’s order to a military commander to limit the production of certain oil wells pursuant to a proclamation that the counties in which the oil wells were located were in “‘a state of insurrection, tumult, riot, and a breach of the peace,’ and declaring ‘martial law’ in that territory.” The Supreme Court, after referencing Martin on executive decision-making being “conclusive,” added that “[t]he nature of the power also necessarily implies that there is a permitted range of honest judgment as to the measures to be taken,” and that “[s]uch measures, conceived in good faith, in the face of the emergency, and directly related to the quelling of the disorder or the prevention of its continuance, fall within the discretion of the executive in the exercise of his authority to maintain peace.” Importantly, the Court concluded that “[w]hat are the allowable limits of military discretion, and whether or not they have been overstepped in a particular case, are judicial questions.” (Emphasis added.) The Court upheld the district court’s findings that there was no military necessity or exigency that justified the governor’s order.
2. If reviewable, how much deference should be afforded to the president’s determinations that the statutory preconditions for federalization and deployment have been met?
There is no reason to believe that the standard for reviewing the president’s determinations regarding the statutory predicates should be any different between § 12406 and the Insurrection Act, yet what standard should be applied remains an open question.
Two Ninth Circuit panels, ruling on motions to stay injunctions in California and Oregon pending appeal, concluded that a high degree of deference must be given to the president’s determination, but rejected the United States’ argument that the president’s findings are unreviewable. Instead, drawing on Sterling, they applied a standard of review limited “to ensur[ing] that it reflects a colorable assessment within a ‘range of honest judgment.’” In the California stay appeal, en banc review was denied, with 11 judges filing a dissenting statement arguing that the level of deference should have been reviewed by the full court. In the Oregon case, en banc review was granted.
In the Seventh Circuit, the panel agreed with the Ninth Circuit that a great level of deference should be given to the president’s determination, but did not resolve what standard should apply because it concluded the Chicago deployment was not justified even under a highly deferential standard.
3. What facts constitute a “rebellion or danger of rebellion against the authority of the United States” or the other prerequisites in § 12406 and the Insurrection Act?
In none of the California, Oregon, and Illinois challenges to the 2025 federalizations and deployments did the lower courts agree with the United States that the precondition in § 12406(2) of a “rebellion or danger of rebellion” had been met. The district courts each held that the protests did not constitute a rebellion or danger of rebellion after reviewing the text and historical meaning of “rebellion.” Agreeing with the California and Oregon decisions, the Illinois court described it as a “deliberate, organized resistance, openly and avowedly opposing the laws and authority of the government as a whole by means of armed opposition and violence.” The Seventh Circuit substantially agreed with that definition, at least on the motion for stay pending appeal. The Ninth Circuit issued no opinion on the issue, instead staying the district court injunctions in California and Oregon based on an assessed likelihood of success under § 12406(3) that “the President is unable with the regular forces to execute the laws of the United States.” Those conclusions were overruled by the Supreme Court’s decision in Trump v. Illinois, but the proper interpretation of “rebellion or danger of rebellion” under § 12406(2), and the predicates for other statutes, including the Insurrection Act, remain undefined by the Supreme Court.
4. Is § 12406 an exception to the Posse Comitatus Act?
In Newsom v. Trump, the California district court rejected the United States’ belated argument that § 12406 is an exception to the Posse Comitatus Act. The court noted that the Department of Defense had not included it in its own publications listing the exceptions to the PCA and that the deputy commanding general of the forces deployed in Los Angeles understood the PCA to apply to their activities. The court also concluded that, at least as to §12406(3), if it were an exception to the PCA, it would create a loophole in the PCA that would render the Insurrection Act meaningless. This conclusion has not yet been subjected to higher review.
5. What constitutes “execut[ing] the laws” for purposes of the Posse Comitatus Act?
Numerous cases have articulated tests for determining what conduct violates the PCA, i.e., is the use of the military regulatory, proscriptive, or compulsory? Does the military involvement pervade civilian law enforcement activities? And is the involvement direct and active? The California district court, after an evidentiary trial, concluded that the forces deployed in Los Angeles violated the PCA by setting up protective perimeters, traffic blockades, and engaging in crowd-control measures. That ruling has not yet been subjected to higher review.
Trickier questions arise where the government claims that federalized National Guard members (and, in the case of Los Angeles, the deployment of active-duty Marines), are being deployed only to protect federal personnel and property, and do not claim an exception to the PCA. Indeed, the president’s June 2025 executive order authorized federalization and deployment of the National Guard “to temporarily protect ICE and other United States Government personnel who are performing Federal functions, including the enforcement of Federal law, and to protect Federal property, at locations where protests against these functions are occurring or are likely to occur.” Although the judge-made tests for determining what “execut[ing] the laws” means are generally understood to prohibit the military from engaging in core law enforcement functions like arrest, detention, search, and seizure, does that mean that the temporary detention of a person posing an imminent threat to federal personnel would violate the PCA? If so, the protective power may be quite limited in the circumstances where it would be most necessary. If not, isn’t it just an end-run around the PCA?
6. Is there inherent constitutional authority to use the U.S. military and federalized National Guard domestically absent express constitutional or statutory authority?
This question flows naturally from the last, and from the Supreme Court’s decision in Trump v. Illinois, insofar as one of the claimed inherent exceptions is based on Office of Legal Counsel opinions concluding that the president can use the military to protect federal personnel and property without violating the Posse Comitatus Act. As Justice Amy Coney Barrett wrote in Trump v. Illinois, this Executive Branch position is based on its view that “performing such protective functions does not constitute ‘execut[ing[ the laws’ within the meaning of the Posse Comitatus Act.’”
If in fact, the protection of federal personnel and property includes things like temporarily detaining someone who is assaulting a federal agent, or engaging in a search and seizure where there are clear indications a person is carrying a dangerous weapon and poses an imminent risk of harm to a federal agent, then it is hard to see how the protective functions do not include conduct that would violate the PCA. And if such violations are permitted because the protective function is indeed an exception to the PCA, how can such an exception be recognized under Youngstown Sheet & Tube Company v. Sawyer? The Supreme Court there rejected the argument that the president had implied authority to take over steel mills, holding that when a president’s action is not authorized by the Constitution or by an Act of Congress, it is unlawful. Justice Robert Jackson’s concurrence is likewise useful:
When the President takes measures incompatible with the expressed or implied will of Congress, his power is at its lowest ebb, for then he can rely only upon his own constitutional powers minus any constitutional powers of Congress over the matter. Courts can sustain exclusive Presidential control in such a case only by disabling the Congress from acting upon the subject. Presidential claim to a power at once so conclusive and preclusive must be scrutinized with caution, for what is at stake is the equilibrium established by our constitutional system.
7. Does § 502(f) authorize the National Guard to deploy for crime control?
At the time of this publication, National Guard units from several states are deployed in Washington, D.C., pursuant to Section 502(f) of Title 32. Although “other duty” has been accepted to include support operations and missions such as airport security after 9/11, disaster relief, and border operations, general crime control does not seem to be what was contemplated by § 502(f), and is inconsistent with the Tenth Amendment, which reserves the police power to the states.
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Although this is not a full list of open questions with respect to the limits of the president’s power to use the military domestically, it elucidates why more clarity is needed to reduce the potential for abuses that are not only dangerous to public safety, but also undermine the principles that underlie the Declaration of Independence. Among other grievances were that the King “had kept among us, in times of peace, Standing Armies without the consent of our legislatures,” had “affected to render the military independent of and superior to the civil power,” and had “quarter[ed] large bodies of armed troops among us.”
The Solution: A Single Modern Statute, Enforceable Limits, Real Review
Others have proposed reforms to the Insurrection Act over the years, but the questions that have arisen in the second Trump administration require solutions beyond reform of that Act. And although the hyper-partisanship in Congress right now makes passage of legislation particularly challenging, there are good reasons why members of both political parties should want to constrain the president’s authority to deploy the military domestically. At the same time, there are true emergency situations in which such deployments would be warranted. Relying on its Article I powers, Congress should enact legislation that addresses the open questions identified above.
1. Provide for judicial review
At a minimum, Congress should amend the Insurrection Act and 10 U.S.C. § 12406 to make clear that (1) the president’s determination that the predicates for deployment of the military and federalization and deployment of the National Guard are judicially reviewable, and (2) the standard of review should at least ask whether such determination is “conceived in good faith,” based on a colorable assessment of the facts within a “range of honest judgment.” This standard adopts the Supreme Court’s own characterization of appropriate deference to the executive in Sterling, and thus represents the most judicially sustainable compromise between Congress’s constitutional authority under Article I and the president’s authority as the commander-in-chief under Article II. As for interpreting what the statutory terms mean, that is the role of the courts in the absence of definition by Congress, even when it involves statutes for which judicial review is limited.
2. Define statutory terms
In addition to providing for meaningful judicial review, a more ambitious reform would be for Congress to define the terms in both the Insurrection Act and 10 U.S.C. § 12406. Congress could define “insurrection,” “unlawful obstructions, combinations, or assemblages,” and “rebellion against the authority of the United States,” the latter of which is used in both the Insurrection Act’s § 252 and in 10 U.S.C. § 12406. It could also define what it means for any of the above to “make it impracticable to enforce the laws of the United States in any State by the ordinary course of judicial proceedings,” as used in § 252.
For the purposes of § 12406(3), which allows for federalization and deployment whenever “the President is unable with the regular forces to execute the laws of the United States,” Congress could clarify what “regular forces” means. Although the Supreme Court in Trump v. Illinois provided its assessment that “regular forces” “likely refers to the regular forces of the United States military,” that remains just a preliminary conclusion on an emergency motion for a stay. It is also unclear what daylight there is—if any—between it being “impracticable” to enforce U.S. laws for purposes of the Insurrection Act, and the president being “unable” with regular forces to execute U.S. laws for purposes of § 12406(3).
Other terms in need of definitions are in § 253 of the Insurrection Act. For example, what is “domestic violence, unlawful combination, or conspiracy”? Without establishing some baselines, § 253 could be invoked for isolated acts of “domestic violence” that are not comparable to insurrection. Similarly, are there any limits on what is considered to “hinder[] the execution of the laws” that protect the rights of a class of people, or “oppose[] or obstruct[] the execution of the laws of the United States” or “impede[] the course of justice under those laws”? Words like “hinder,” “oppose,” and “obstruct” leave quite a lot of room for interpretation.
3. Better yet, comprehensively overhaul the Insurrection Act and § 12406 to remove overlapping provisions
An even more ambitious reform would be to start over and consolidate the emergency authorities in both the Insurrection Act and 10 U.S.C. § 12406 into a single statute, which also provides for meaningful judicial review. Until 2025, there was little to suggest that § 12406 was anything more than a technical statute used to call forth the National Guard when another authority, like the Insurrection Act, was invoked. Indeed, except for the first provision of § 12406, which allows for the federalization and deployment of the National Guard when the United States “is invaded or is in danger of invasion by a foreign nation,” the other two provisions of § 12406 overlap substantially with the provisions of §§ 252 and 253 of the Insurrection Act. And §§ 252 and 253 themselves contain overlapping provisions. It would provide much-needed clarity for future presidents, state governors, and the courts if there were a single statute that provided the authorization for deployments of the military and federalized National Guard domestically. It would also eliminate any question about whether § 12406 is an exception to the Posse Comitatus Act – the district court in Newsom v. Trump concluded it is not, lest it create a giant loophole permitting federalized National Guard members to engage in domestic law enforcement without any invocation of the Insurrection Act.
In any new comprehensive statute, the terms used should be modernized and defined so that each covers a specific type of conduct that does not overlap with another. Those terms could include “insurrection” and “rebellion or danger of rebellion against the authority of the United States,” as long as the differences between the two are clear. There is little need to add “unlawful combinations,” “assemblages,” “conspiracies,” or “domestic violence” if the terms “insurrection” and “rebellion” are well defined. A conspiracy to commit an insurrection is a crime, but should not support deployment of the military domestically unless and until there is an actual insurrection or one is demonstrably imminent.
Similarly, one statutory term should be used to convey what level of impact an insurrection or rebellion must have on the execution of U.S. law in order to deploy the military and federalized National Guard. Current law is all over the place, using “unable” to execute U.S. law, “impracticable” to enforce U.S. law; “hinders” execution of the law; “opposes or obstructs” execution of the law, and “impedes the course of justice under those laws.”
4. Define the conduct prohibited by the Posse Comitatus Act
The PCA prohibits the military from being used as a “posse comitatus or otherwise to execute the laws” unless “expressly authorized by the Constitution or Act of Congress.” A posse comitatus is a relic of the common law that historically was used by sheriffs to mobilize county citizens to catch outlaws or keep the peace. In this age of modern police forces and mutual aid agreements between law enforcement, there is little need for such citizen bands, and certainly no reason for military members to take part. If the PCA is amended to explicitly define what “execut[ion] of the law” it prohibits the military from engaging in, as it should be, there is no need to include a vague term like “posse comitatus” within its prohibitions.
As noted above, the courts have set out a variety of tests for determining what conduct violates the PCA, but the tests themselves are not models of clarity. At a minimum, a prohibition on the military engaging in arrests, detentions, search, or seizure would be much clearer, as those terms are well defined in caselaw. To the extent there are exceptions, such as for arrest and temporary detention where there is a demonstrable risk of imminent injury or death, limited in time until the person can be turned over to civilian law enforcement, such exceptions should be explicitly laid out in the statute (including their time limitations and other safeguards). The same goes for searches and seizures in extenuating circumstances.
As the experience in Los Angeles bore out, however, limiting the conduct prohibited by the PCA to arrests, detentions, search, and seizure may be inadequate to protect against the military being used to pervade domestic law enforcement. That is what led to the California district court’s holding that establishing protective perimeters, traffic blockades, and engaging in crowd control violated the PCA. These police functions should be left to state and local law enforcement, or, if necessary, the National Guard in state active duty or Title 32 hybrid status. The PCA should be amended to be clear that these functions are off limits to the military absent proper invocation of a statutory exception.
Beyond defining the prohibited conduct, reform of the PCA should include enumeration of its statutory exceptions. If the Insurrection Act and § 12406 are not consolidated into a single statute as recommended above, the PCA should be clear that § 12406 is not an exception. And the Act should be amended to include a private right of action to challenge violations, including to seek injunctive relief.
5. Revise 32 U.S.C. § 502(f) to define “other duty”
Section 502(f) of Title 32 was designed to provide a mechanism for federal departments and agencies to request National Guard assistance, and it specifically includes “support of operations or missions undertaken by the member’s unit at the request of the President or Secretary of Defense.” When in Title 32 hybrid status, National Guard units are not constrained by the Posse Comitatus Act and may engage in domestic law enforcement. Limiting “other duty” is necessary to ensure that § 502(f) does not devolve into roving military patrols performing the role of civilian law enforcement—something that was not only an anathema to the framers of the Constitution, but remains deeply inconsistent with American democratic principles today. Congress should revise § 502(f) to enumerate what “other duty” covers, perhaps including things that presidents of both parties have used it for, such as airport security, border protection at the border, and responding to natural disasters, but should be clear that “other duty” does not include general crime control.
6. Clarify what, if any, inherent constitutional authority the president has to deploy the U.S. military and federalized National Guard domestically
If the president has any inherent or implied constitutional authority to deploy the military domestically, it likely would not be a power that Congress could take away by statute. But the courts are responsible for interpreting the Constitution, and in the appropriate case, should clarify the limits of that authority. The argument for emergency authority to prevent loss of life, wanton destruction of property, and to restore governmental functions when there are large-scale civil disturbances or natural disasters is stronger than the argument for inherent authority to protect federal property and functions, but duly enacted statutes make most if not all uses of inherent authority unnecessary. In the case of the so-called emergency authority, the Insurrection Act and options for deployment of the National Guard in Title 32 hybrid status should be sufficient. And in the case of the protective power, the protection of federal property and functions should generally be handled by civilian law enforcement. To the extent that state and local law enforcement refuse to protect federal property and functions, and federal civilian resources are inadequate, the provisions of the Insurrection Act that allow for deployments when insurrections or rebellions meet the requisite level of obstruction of the execution of U.S. law should suffice. Making clear that there is no inherent constitutional authority to deploy the military to protect federal property and functions would also eliminate the easy end-run around the Posse Comitatus Act.
7. Include a cause of action for enforcement of laws barring military at the polls
Although the 2025 deployments were all in response to protests against ICE activity, threats of military deployments to voting locations this November or in future elections must be taken seriously. Such deployments are unlawful under current law.
Section 592 of Title 8 prohibits civil and military authorities from ordering “troops or armed men at any place where a general or special election is held, unless such force be necessary to repel armed enemies of the United States.” It makes violations of that prohibition subject to criminal penalties.
Section 10102 of Title 52 states that: “No officer of the Army, Navy, or Air Force of the United States shall prescribe or fix, or attempt to prescribe or fix, by proclamation, order, or otherwise, the qualifications of voters in any State, or in any manner interfere with the freedom of any election in any State, or with the exercise of the free right of suffrage in any State.”
Although these prohibitions are clear, neither statute provides a cause of action to challenge violations. Congress should amend the statutes to provide a private right of action, including for injunctive relief.
8. Require congressional approval after any deployment of the military domestically
Regardless of the authority relied on for the deployment, Congress should require the president to provide a report to Congress within a set period of time after any domestic deployment of the military or federalized National Guard. It would be helpful to include a requirement that the president certify to the emergency situation (the “rebellion” or the like) that necessitated the deployment, and whether it remains ongoing. And, similar to the War Powers Resolution, any such deployment should be limited in time unless Congress authorizes the deployment, with a clear funding termination should the deployment exceed that time limit and judicial review available on an expedited basis on that question.
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The above solutions are some of the possibilities for addressing the questions that remain unresolved about the authorities to deploy the military domestically. Other solutions, though less permanent, could include Department of Defense and National Guard regulations limiting the activities in which deployed forces may engage. Indeed, the California court in Newsom v. Trump relied on DOD training materials to conclude that the military deployed in Los Angeles violated the Posse Comitatus Act. Given the increased threats of misuse of current authorities, it is incumbent upon Congress to take this issue seriously—as the courts did in 2025 and 2026—and act to clarify the constraints on the president’s power, subject to judicial review.
