The Supreme Court Tells Pres. Trump He Can Only Use The Insurrection Act To Assist ICE In Enforcing Immigration Law.
The language of the statute relied upon is a historic anachronism that only Congress can fix, or it can watch as the Executive uses the only tools SCOTUS says he has -- the Army and Marines.
On December 23, 2025, the Supreme Court denied the Trump Administration’s request to stay a lower court order in Illinois that National Guard troops could not be used as a protective force in and around Chicago for federal immigration officers enforcing federal immigration law. The matter had been pending before the Supreme Court for more than two months, including for 6 weeks after Justice Barrett requested additional briefing on what the phrase “regular forces” meant in the statute the Trump Administration was relying on. The Court’s decision was that the statute’s phrase “regular forces” likely refers to the regular forces of the United States military, and not civilian law enforcement agencies of the Executive Branch — something BOTH sides had agreed upon.
Here is the central finding of the Court’s very short and unsigned opinion:
We conclude that the term “regular forces” in § 12406(3) likely refers to the regular forces of the United States military. 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….” 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.
At this preliminary stage, the Government has failed to identify a source of authority that would allow the military to execute the laws in Illinois. The President has not invoked a statute that provides an exception to the Posse Comitatus Act. Instead, he relies on inherent constitutional authority that, according to the Government, allows him to use the military to protect federal personnel and property. But the Government also claims—consistent 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. See Supp. Letter Reply Brief for Applicants 8; 1 Supp. Op. OLC 343, n. 1 (1971) (collecting sources). If that is correct, it is hard to see how performing those functions could constitute “execut[ing] the laws” under § 12406(3)…. Thus, at least in this posture, the Government 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. We need not and do not address the reviewability of findings made by the President under §12406(3) or any other statute.
Under this holding, to justify use of the National Guard the Administration must show an inability to enforce the law with law enforcement and the active duty military. The Trump Administration never sought to do so because both parties in the Illinois case agreed the “regular forces” was NOT a reference to the active duty military. Since the Trump Administration had not made a factual case in the lower courts that it was not able to “execute the laws” with the active duty military, the precondition for employing the National Guard for that purpose had not been met.
While the announced vote was 6-3, with the Chief Justice, Justice Kavanaugh, and Justice Barrett joining the Court’s three liberals, the Court really stands at 5-4 because Justice Kavanaugh signaled in a concurring opinion that it is the current “record” that is insufficient, and it is within the authority of the President to supplement the record to get his vote. More on Justice Kavanugh farther down below.
