The U.S. Supreme Court on Oct. 29 delayed ruling on whether the Trump administration’s deployment of National Guard troops in Chicago is lawful.

Instead, the justices directed attorneys for the Trump administration, state of Illinois, and city of Chicago, to address what the term “regular forces” means in a federal law that allows the president to take command of state National Guard troops.

Illinois and Chicago filed a lawsuit on Oct. 6 after Secretary of War Pete Hegseth invoked Section 12406 of Title 10 of the U.S. Code to federalize up to 300 members of the Illinois National Guard and up to 400 members of the Texas National Guard for deployment in Chicago.

Illinois Gov. JB Pritzker on Oct. 5 called Trump’s deployment of the troops an “invasion.”

“There is no reason a president should send military troops into a sovereign state without their knowledge, consent, or cooperation,” the Democratic governor said at the time.

The Supreme Court issued a new, unsigned order in the case spelling out what it requires the lawyers for the litigants to do before it issues a ruling. No justices dissented.

A president may take over, or federalize, state National Guard troops under certain emergency circumstances. The Trump administration argues the deployment is needed to help the federal government enforce federal immigration laws in Chicago.

Section 12406 allows the president to federalize state troops when he finds himself “unable with the regular forces to execute the laws of the United States.”

In that situation, 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,” according to the statute.

Specifically, the Supreme Court ordered the attorneys to file supplemental briefs dealing with the following question: “Whether the term ‘regular forces’ refers to the regular forces of the United States military, and, if so, how that interpretation affects the operation of 10 U. S. C. [Section] 12406(3).”

U.S. District Judge April Perry of the Northern District of Illinois issued an order on Oct. 9 that prevented the administration from federalizing and deploying National Guard troops within the state. Perry said that the administration was likely violating the 10th Amendment.

The amendment states that “powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.

Perry said deploying National Guard members “is likely to lead to civil unrest, requiring deployment of state and local resources to maintain order.” The judge said evidence is “overwhelming” that “the provocative nature of ICE’s enforcement activity has caused a significant increase in protest activity.”

The U.S. Court of Appeals for the Seventh Circuit ruled on Perry’s order on Oct. 16. The appeals court allowed President Donald Trump to federalize members of the National Guard, but prohibited their deployment.

The U.S. Department of Justice said in its emergency application to the Supreme Court that the district court judge had “impermissibly substitut[ed] the court’s own judgment for the President’s on military matters.”

U.S. Solicitor General D. John Sauer said in the application that Trump “determined that the situation in Chicago had become unsustainably dangerous for federal agents, who now risk their lives to carry out basic law enforcement functions.”

The Supreme Court directed attorneys involved in the case to file briefs by Nov. 10, to be followed by reply briefs due by Nov. 17.

Sam Dorman contributed to this report.

This article by Matthew Vadum appeared Oct. 29, 2025, in The Epoch Times.