Is the President Subject to the Posse Comitatus Act?

An issue left unresolved in Trump v. Illinois.

[This post is co-authored with Professor Seth Barrett Tillman.]

The Supreme Court's decision in Trump v. Illinois (2025) was issued in a preliminary context, and without the benefit of oral argument. Some scholars have argued that this case is basically moot, but others believe the Executive Branch will continue litigating this case in the normal course. It would be problematic for the presidency to have this interim ruling remain on the books for generations to come, without a fulsome resolution by the Supreme Court.

We turn to the central statute at issue in the case.

10 U.S.C. § 12406(3) provides:

Whenever--the President is unable with the regular forces to execute the laws of the United States; …

(3) 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. 

In Trump v. Illinois, the Court's focus was on the meaning of "regular forces," but there was less focus on the meaning of "unable." Here is the Court's analysis:

This interpretation means that to call the Guard into active federal service under §12406(3), the President must be "unable" with the regular military "to execute the laws of the United States." Because the statute requires an assessment of the military's ability to execute the laws, it likely applies only where the military could legally execute the laws. Such circumstances are exceptional: Under the Posse Comitatus Act, the military is prohibited from "execut[ing] the laws" "except in cases and under circumstances expressly authorized by the Constitution or Act of Congress." 18 U. S. C. §1385. So before the President can federalize the Guard under §12406(3), he likely must have statutory or constitutional authority to execute the laws with the regular military and must be "unable" with those forces to perform that function. [Slip. op. at *2.] 

Under the Court's view, the President is able to federalize the national guard only (i) when he has legal authority to deploy the regular forces domestically to execute the laws, and (ii) when those regular forces are insufficient. According to the Court's position, legal authority to use regular forces domestically to execute the laws is a necessary, but not a sufficient condition to federalize the National Guard. On the facts before it, the Court found that the Posse Comitatus Act prohibits the President from using the regular forces to execute the laws. [Slip op. at *2.] The Court concluded that President Trump could not federalize the National Guard because the President was "unable" to lawfully deploy the regular forces of the United States. In other words, the Court ruled against the President because he could not satisfy the necessary condition. But for the Court's argument to work, the President must be subject to the Posse Comitatus Act.

In Youngstown Sheet & Tube Co. v. Sawyer (1952), Justice Jackson took the position, absent analysis, that the President was bound by the Posse Comitatus Act. Jackson, a former Attorney General, wrote "Congress has forbidden [the President] to use the army for the purpose of executing general laws except when expressly authorized by the Constitution or by Act of Congress." This question was not at issue in Youngstown. To be sure, Jackson wrote his concurrence closer in time to when the Posse Comitatus Act was adopted. But it is not clear that Jackson's analysis still stands in light of the Court's more recent precedents. 

Let's walk through the analysis. The Posse Comitatus Act, 18 U.S.C. § 1385, provides:

Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army, the Navy, the Marine Corps, the Air Force, or the Space Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both. (emphasis added).

The Supreme Court's analysis in Trump v. Illinois turned on the President's inability to use the regular forces for purposes of domestic law enforcement. And this analysis relied on the President being subject to the Posse Comitatus Act. But does the Posse Comitatus Act apply to the President? To be sure, this argument has nothing to do with whether the President is an "officer of the United States." Rather, we rely on well developed principles of statutory interpretation. 

The statute does not expressly reference the President. Franklin v. Massachusetts (1992) and related cases articulated a clear statement rule. See also, e.g., Nixon v. Fitzgerald, 457 U.S. 731, 748 & n.27 (1982) (Powell, J.). Under this canon of avoidance, if the President is not expressly named in a statute, the courts should not presume that Congress intended to limit the President's power. The Office of Legal Counsel has recognized this clear statement rule. See also, e.g., Memorandum from William H. Rehnquist, Assistant Attorney General, for the Honorable Egil Krogh, Staff Assistant to the Counsel to the President, Office of Legal Counsel, Re: Closing of Government Offices in Memory of Former President Eisenhower 3 (Apr. 1, 1969); Memorandum from Antonin Scalia, Asst. Att'y Gen, to Honorable Kenneth A. Lazarus, Re: Applicability of 3 C.F.R. Part 100 to the Pres. and V.P., OLC, at 2 (Dec. 19, 1974). This sort of avoidance would be especially appropriate with the Posse Comitatus Act given that the statute potentially intrudes on the President's Article II powers.

Moreover, the Posse Comitatus Act imposes criminal penalties of up to two years in prison. Under the immunity doctrine from Trump v. United States (2024), a criminal prosecution against the President is likely barred where the statute implicates the President's "core" presidential powers. The Court concluded that "At least with respect to the President's exercise of his core constitutional powers, this immunity must be absolute." See Illinois v. Trump, Civil A. No. 25-cv-12174, 2025 WL 2886645, at *19 (N.D. Ill. Oct. 10, 2025) (April M. Perry, J.) ("The Posse Comitatus Act makes it a criminal offence to use the Army, Navy, Marine Corps, and Air Force to 'execute the laws' unless expressly authorized by Congress. 18 U.S.C. § 1385. And as Justice Jackson in his well-known Youngstown concurrence has recognized, while this prohibition likely does not apply to hold the President criminally liable, the Act nonetheless operates to 'forbid[ ]' the President 'to use the army for the purpose of executing general laws except when expressly authorized by the Constitution or by Act of Congress.' Youngstown Sheet & Tube Co., 343 U.S. at 644–45 (Jackson, J., concurring in the judgment)." (second set of italics added)), aff'd in part, rev'd in part, 155 F.4th 929 (7th Cir. 2025) (per curiam), stay denied, Trump v. Illinois, No. 25A443, 2025 WL 3715211, 607 U.S. —- (Dec. 23, 2025) (per curiam). 

In Trump v. United States, the majority opinion did not expressly reference the clear statement rule. Nevertheless, we believe the clear statement rule animated the Court's immunity analysis. The relevant criminal statutes that Trump had been charged with violating were generally worded, and did not expressly apply to the President. For example, during oral argument, Justice Kavanaugh asked John Sauer, counsel for defendant Trump, "I assume you would think that a clear statement has to be required, a clear statement in the statute covering the president, if the president's official acts are going to be criminalized?" Later, Kavanaugh told Sauer, "there's a lot of official powers that are not exclusive to the president under his Article II authority, but for those, I understood you to be saying, at a minimum, there would need to be a clear statement in the statute referencing the president so that the president's on notice and can conduct himself or herself accordingly." Sauer replied, "That's absolutely correct, and that would be consistent both with Franklin [v. Massachusetts] and and Public Citizen [v. Department of Justice] and [other] cases--a long series of other clear statement rule cases."

We think Justice Barrett read the majority opinion the same way we do here. Indeed, Justice Barrett, in her partial concurrence, felt the need to reject the application of this substantive canon because she understood the majority to be following this canon. She said she would not apply either the "avoidance canon" or the "clear-statement rule." Justice Barrett favorably cited Justice Kennedy's Public Citizen concurrence which declined to apply the avoidance canon.

The Posse Comitatus Act does not expressly reference the President by name, and it also arguably intrudes on "core" presidential powers. For these reasons, the clear statement rule and the immunity doctrine work in tandem and are mutually supporting. Working together, these doctrines reinforce that the President would not be subject to the Posse Comitatus Act. In Trump v. Illinois, the Supreme Court did not have occasion to address the applicability of Trump v. United States' presidential immunity doctrine with regard to the Posse Comitatus Act.

The Trump v. United States immunity doctrine would only shield the President against a prosecution, but that doctrine would not shield his subordinates involved in law execution subject to the President's direction. By contrast, a rogue military commander who unilaterally directs military subordinates to engage in law execution would face liability under the Posse Comitatus Act. But we do not think it is so clear that a commander violates the statute if the commander follows the President's otherwise lawful order, after the President has given orders to direct the regular forces to engage in law execution. In this set of circumstances, we suggest that it is the President, and not the commander, who has "willfully" directed regular forces to engage in law execution. "An act is done 'willfully' if done voluntarily and intentionally and with the specific intent to do something the law forbids." (emphases added) U.S. Department of Justice, U.S Attorneys' Manual/Criminal Resource Manual, Section 910 Knowingly and Willfully. It is not frivolous to suggest that an act taken by a subordinate military officer carrying out a superior's orders (including the President's) is not a "voluntary" act, and therefore, such an act is not "willful." Likewise, depending on the circumstances, such a subordinate military officer may also lack "the specific intent to do something the [Posse Comitatus Act] forbids." But, in any event, we do not need to settle this subsidiary legal issue here.

Relatedly, are Article III judges subject to the Posse Comitatus Act? If an Article III judge has a case before him, where the court has subject matter jurisdiction, and the judge issues an order, but it is not enforced by the U.S. Marshals, such a judge might—rightly or wrongly—call out a posse composed of the regular forces to enforce his judicial orders. Cf. Ex parte Merryman 17 F. Cas. 144 (1861) (No. 9487) (Taney, C.J., in chambers) ("[T]he chief justice said, that the marshal had the power to summon the posse comitatus to aid him in seizing and bringing before the court, the party named in the attachment, who would, when so brought in, be liable to punishment by fine and imprisonment; but where, as in this case, the power refusing obedience was so notoriously superior to any the marshal could command, he [the chief justice] held that officer excused from doing anything more than he had done."). This hypothetical is perhaps not so far-fetched. In recent months, federal judges have worried that the Trump Administration would withdraw U.S. Marshals Service's protection from federal judges. Any effort to criminally prosecute an Article III judge for his error (assuming this course of action to be an error) would be blocked by the doctrine of absolute judicial immunity. 

We recapitulate our position. First, there is a substantial argument that the Posse Comitatus Act does not apply to the President in light of the clear statement rule. Second, even assuming the President is subject to the Posse Comitatus Act, the doctrine announced in Trump v. United States, insofar as the Posse Comitatus Act intrudes on "core" executive powers, immunizes the President against prosecution. Third, subordinate military officers, in compliance with Presidential orders, who direct their subordinates to engage in law-execution, are not voluntarily and willfully violating the Posse Comitatus Act. If any of these arguments are correct, then we think the emergency docket ruling in Trump v. Illinois, that the President is unable to use the regular forces and the federalized National Guard, warrants some further scrutiny when this case returns to the merits docket.

Comments

[MollyGodiva]

More BS from Josh. The "clear statement rule" is not in the Constitution. It was made up in order to give the president more power. The "core presidential power" is commanding the military under the laws set by Congress and when Congress authorizes military force. The Posse Comitatus Act is Congress saying when the military can not be used. Even if you hold the Posse Comitatus Act does not apply to the president, it will apply to everyone below him.

It is scary how Republicans look at limits the Constitution and federal law puts on the president and try to argue they mean the exact opposite.

[Enrique]

Although I could do without Josh's better-late-than-never Heritage Foundation virtue signalling, his analysis here is spot on. Plus, at the end of the day, it's the president or congress -- not the courts -- who gets to decide when force is being used in contravention of this the posse comitatus act

[Reallynotbob]

"It is not frivolous to suggest that an act taken by a subordinate military officer carrying out a superior's orders (including the President's) is not a "voluntary" act, and therefore, such an act is not "willful." Likewise, depending on the circumstances, such a subordinate military officer may also lack "the specific intent to do something the [Posse Comitatus Act] forbids." But, in any event, we do not need to settle this subsidiary legal issue here."

Make no mistake, this IS the "just following orders" doctrine.

Blackman's syllogism:
1. The President is neither a "whoever" nor an "officer," and can be restrained by Congress only by including "The President" among those subject to the law. (Note the implication that no laws bind the President otherwise, which is a different question from immunity.)
2. Congress may not intrude on the President's "core" executive power without regard to the "Faithfully Execute" or "Take Care" clauses. In other words, the Executive is no longer a caretaker or administrator of the government's powers, but a freely operating independent force ungoverned by Congress.
3. Only SCOTUS (if even that) has the ability to define the "core" executive function. Congress does not.
4. As a matter of law, officers acting at Presidential direction lack the mens rea necessary to willfully violate the law.
5. In any event, the President can give a plenary pardon to all officers.

And voila, the checks and balances are no more.

[John F. Carr]

"It is not frivolous to suggest that an act taken by a subordinate military officer carrying out a superior's orders (including the President's) is not a 'voluntary' act, and therefore, such an act is not 'willful.'"

The UCMJ anticipates this argument. Obedience to orders is a defense to criminal prosecution unless the officer knew or should have known the order was not legal. The courts have given notice that orders to have the National Guard enforce the law in Chicago are not legal. Officers in other cities should be having second thoughts too. The situations in those cities might be distinguishable.

[Reallynotbob]

Understood, but Blackman's argument sidesteps the UCMJ by arguing there is no actionable scienter in the minds of officers who follow a President's illegal order. According to Blackman, the President is the only actor with intent and the President's instructions cannot violate law.

[windycityattorney]

First, lots of references to "we." We believe...we conclude... who is we? Is Josh writing for himself here or some group?

Second, as a matter of originalism, the analysis while technically solid based on precedent, seems to run into a major problem. The founders did not like nor trust standing armies or future leaders. They did not want offensive military powers solely in the hands of a single individual. There is a reason Congress has a specific enumerated power as regards declaring war; and Congress has the power of the purse (i.e, to fund or de-fund military adventures at will despite what the president may wish to do).

What is also striking -is that the statute relied upon by the executive branch talks about invasions, rebellions and inability to enforce the law "with regular forces" in the same statute. So clearly, we are not talking about run of the mill criminal or civil law enforcement. Which is in fact the circumstance in which the statue was invoked. The dissent does such a poor job of analysis here; talking about obstructions and vandalism but NOT the fact that immigration detentions in IL are up substantially. Ipso Facto, the government is clearly not 'unable' to enforce immigration laws. They are enforcing them more than ever. They are just annoyed.

The government is acting like all these preconditions are mutually exclusive and I am not so sure that is the way to properly read the statute as a whole. Clearly the statute contemplates dire circumstances. Inconvenience and protesting and mild property destruction (slashing tires of ICE vehicles) is already criminal; but is nothing in comparison to a proper invasion. Let's see...compare slashing tires with: blowing up the entire ICE facility with a JDAM.

Given the founders distrust of military powers; its distrust of standing armies, it's putting the military under civilian control, and assigning major military decisions (and the military's funding) to the legislative branch, etc... i am not so sure this case is a good case to massively expand executive power to call forth the fucking nat'l guard because that bitch midget Greg Bovino's officers are being yelled at rudely?? Not to mention the fact that the district court found almost all of the government's submissions not-credible or supported by the available evidence. But ya. Die on this stupid hill. And then don't complain when the next president of a different party abuses the precedent you are now advocating.

There isn't an originalist or even textualist argument to support the govt's position here. Political actors using the military for political and intimidation reasons, without the consent of the governor's whose state they are using them from, is inherently suspect. It is clearly statutorily designed as a last resort measure; not a first. And what did the President attempt before federalizing the guard? Cook County sheriff deputies and IL State Police went to the ICE facility on their own to maintain order and when our governor tried to coordinate with the feds, they were met with silence. So they can shove their fake emergency straight up their ass and go home.

[Krayt]

Returning triumphant generals were not allowed to bring their troops into Rome and all that.

It becomes questionable whether we have a civilian head of the military in all but name if he stomps them all about the homeland. Declaring he has this honor constitutionally, in spite of Congress, is unshackling the one and exactly wrong person history counsels against, over and over again, literally for millenia.

There is much to be said about Nixon's somewhat maligned "it's not illegal if the president does it" in a context of Congress passing laws directing the President in use of his plenary powers. This is not one of those situations.

[Longtobefree]

It's OK if a Republican does it.

"On September 24, Eisenhower invoked the Insurrection Act of 1807 to enable troops to perform domestic law enforcement. The president ordered the 101st Airborne Division of the United States Army to Little Rock—initially without its black soldiers at the request of the Department of Justice—and federalized the entire 10,000-member Arkansas National Guard, taking it out of Faubus's control. Two segregationists were injured in clashes with federal troops on September 25; one who was struck in the face with a buttstock after trying to grab a soldier's rifle, and a second who received a minor bayonet wound to the arm."

[Longtobefree]

Noun
insurrection (countable and uncountable, plural insurrections) (also figuratively)

(uncountable) The action of part or all of a national population violently rising up against the government or other authority; (countable) an instance of this; a revolt, an uprising; specifically, one that is at an initial stage or limited in nature.

[OpinionsVary]

Trump hasn't used the Insurrection Act. The point of the current debate is that the SCOTUS found the Posse Comitatus Act doesn't, by its self, provide legal authority for federalised national guard troops to enforce civilian law. The Insurrection Act does grant that authority. So if you invoke the Insurrection Act (and for the sake of argument we'll assume the Insurrection Act is invoked legally and correctly in this hypothetical), you can use regular troops to enforce law and, if needed, can then call up the national guard to do the same. But absence a law allow regular troops to enforce civilian law, the Posse Comitatus Act doesn't allow federalised national guard to do so.

[SimonP]

I do not know if the quality of this post is typical of the Josh/Seth tag team - I typically do not waste my time on these. But having wasted the time on this post, I have to observe that this could have done with a bit less haste-to-post.

The immunity argument, of course, depends entirely on whether the President is acting within his legal authority. It is not enough to say that the President is "arguably" exercising a "core" authority granted to the President by the Constitution. You must point to the "core" authority at issue and explain how the President is acting within it. I suspect the reason you do not do this is that it does not help your argument. Because, while the President is admittedly the "commander in chief" of the American military, Congress is the branch authorized to raise, fund, and regulate the military and its use. The President does not have plenary authority to use the military for any purpose he personally deems proper. Congress may, and indeed has, restricted his ability to do so.

It is not a trivial nuance to be passed with a hand-wave. The President is not "absolutely immune" when he acts without legal authority, and "arguably" the Posse Comitatus Act divests him of the authority to direct the military to enforce domestic law. You cannot question-beg your way to the conclusion that the divestiture is invalid under the Court's recently-invented "immunity doctrine"; you must establish that the divestiture purports to take from the President an authority that the Constitution grants to him directly.

Moreover, while the "clear statement" argument is not necessarily inconsistent with the "immunity" argument, as applied to the President himself, your attempt to bootstrap the entire chain of command under the skirt of presidential immunity curiously requires assuming that the only person who could possibly be subject to the Posse Comitatus Act (assuming everyone follows orders) is the President himself. On this reading, the only people who could possibly be subject to the Posse Comitatus Act's proscription would be - what? Commanders going rogue or without orders, to enforce domestic law?

It is difficult to predict what this Court will ultimately do with its holding on presidential immunity. They likely only intended to prevent a parade of tit-for-tat prosecutions, from one presidency to the next, and anticipated that invocations of the "doctrine" would come up only rarely, giving them the opportunity to provide necessary clarification around the edges of "official action" and "presumptions of immunity", among other things. They likely did not expect that their holding would lay the groundwork for a military dictatorship, and I'll admit I don't quite understand the enthusiasm among conservative legal "scholars" to push us as close to that outcome as they can. But I hope, for all of our sake, that the middle-three conservative justices have a bit more sense - and commitment to sound reasoning (perhaps Kavanaugh could be persuaded) - than either of you seem to.

[MollyGodiva]

"They likely did not expect that their holding would lay the groundwork for a military dictatorship,"

Oh they totally did. What else do you expect when you give immunity to someone who spearheaded an attempted coup?

[LawTalkingGuy]

"It is not frivolous to suggest that an act taken by a subordinate military officer carrying out a superior's orders (including the President's) is not a "voluntary" act, and therefore, such an act is not 'willful.'"

I think this is borderline frivolous because that's generally not what "voluntary" means in the context of committing a criminal offense. Voluntariness typically refers to a physical act of the body (the actus rea). So if a commander orders the arrest of someone and a solider physically makes the arrest in violation of Posse Comitatus because the President told them to...they are committing a voluntary act by giving an order and physically following it.

Your better (but still awful) argument is that this is a specific intent statute that requires the offender and solider to specifically intend to violate the Act. They would argue that they didn't form that intent because they actually believed they could follow the law and the President's order.

[ReaderY]

In general, the line of argument whereby Congress imposes a criminal penalty and the rules of criminal law are then used to make conduct that would clearly be prohibited without the penalty legal strike me as one of the very strange consequences of the lawyering business.

[ReaderY]

As I think about it, I am having a difficulty with the Supreme Court’s approach.

My problem is this. The Constitution expressly grants Congress the power “to provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections, and repel Invasions.” But while Congress has the power “to maintain and support an Army,” there is no separate power to call forth the army to execute the laws. Similarly, the Guarantee Clause permits the United States to summon the military against domestic violence at a state’s request.

Now, it seems clearly established that the regular army can be used to suppress insurrections and repel invasions. But I am wondering if the Framers’ choice of language suggests a preference for using the militia over the regular forces when it comes to things like executing the laws and suppressing domestic violence. This strikes me as being in tension with the idea that the militia are to be used as a reserve availanle only when the regular army is insufficient.

[ReaderY]

It would seem impeachment and conviction by the Senate would remove a President’s otherwise-existing immunity. “But the party convicted shall nonetheless be subject to indictment, trial, and judgment according to law.”

[MollyGodiva]

Also SCOTUS could overrule that dumb ass decision.