Is the President Subject to the Posse Comitatus Act? |
An issue left unresolved in Trump v. Illinois.
Josh Blackman | 12.30.2025 2:31 PM
[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........