Supreme Court Refuses to Lift Bar on President Using National Guard in Illinois

Today the U.S. Supreme Court issued a brief decision in Trump v. Illinois, No. 25A443. The Court held that 10 U.S.C. § 12406(3) does not authorize the President to federalize the Illinois National Guard for the purpose of protecting federal personnel and property in Illinois.

I noted in this post some problems with that particular statute, including its requirement that orders be issued through the state governor. The Supreme Court’s decision focuses on a different aspect of the statute, the condition that “the President is unable with the regular forces to execute the laws of the United States.” Today’s opinion holds that the reference to “regular forces” limits the statute to laws that the military can enforce, and those are few and far between given the Posse Comitatus Act.

My previous post noted that using military forces to enforce laws in recalcitrant states is better done under one of the surviving remnants of the Ku Klux Klan Act of 1871.

As is common in these summary cases, the opinion of the court is brief and not designated as authored by any justice.

Justice Kavanaugh wrote an opinion concurring in the judgment. He agrees with the result but thinks the language of the opinion goes too far. He also notes that the opinion does not address the statutes I mentioned earlier.

Justice Alito, joined by Justice Thomas, dissent. They are particularly upset with the majority for going beyond the arguments made by the parties.

“ ‘In our adversarial system of adjudication, we follow the principle of party presentation.’ ” Clark v. Sweeney, 607 U. S. ___, ___ (2025) (per curiam) (slip op., at 2) (quoting United States v. Sineneng-Smith, 590 U. S. 371, 375 (2020)). If a party passes up what seems to us a promising argument, we do not assume the role of advocate. Instead, we normally decide the questions that the parties choose to present.

In this case, the Court has unnecessarily and unwisely departed from standard practice. It raised an argument that respondents waived below, and it now rules in respondents’ favor on that ground. To make matters worse, the Court reaches out and expresses tentative views on other highly important issues on which there is no relevant judicial precedent and on which we have received scant briefing and no oral argument.

Justice Gorsuch also dissents and is also uncomfortable with the way important issues are decided in this case.

In the present posture of this case, I am not comfortable venturing an answer to any of those questions. This Court has never decided a case about the meaning of §12406(3), let alone explored its interaction with other statutes in the field or the Constitution. Nor do we have much help on many of these matters from the parties’ briefs before us, understandably given that this case comes to us in an interlocutory posture on a highly compressed schedule.