Illinois Gov. J.B. Pritzker launched a blistering attack on President Donald Trump Tuesday, accusing him of sending National Guard troops into Democratic-led cities like Chicago and Portland out of personal obsession and mental decline.

“This is a man who’s suffering dementia,” Pritzker said in an interview with the Chicago Tribune. “This is a man who has something stuck in his head. He can’t get it out of his head. He doesn’t read. He doesn’t know anything that’s up to date. It’s just something in the recesses of his brain that is effectuating to have him call out these cities. And then, unfortunately, he has the power of the military, the power of the federal government to do his bidding, and that’s what he’s doing.”

The comments came as Trump’s administration began deploying 300 members of the Illinois National Guard for at least 60 days, despite objections from Pritzker and other state and local leaders. Troops from Texas were also seen gathering at a U.S. Army Reserve training center in Elwood, Illinois.

The White House claims the troops are needed to protect federal facilities tied to immigration enforcement efforts, mirroring Trump’s deployment to Portland, Oregon. Illinois and Chicago have filed legal challenges, arguing the move violates the Posse Comitatus Act, which bans the use of the U.S. military for domestic law enforcement.

“We’re not going to go to war between the state of Illinois and the federal government,” Pritzker said. “But we are monitoring everything they’re doing, and using that monitoring to win in court.”

A federal judge in Chicago is expected to hear the case this week. Pritzker, a potential 2028 Democratic presidential contender, said the courts remain the best tool to block what he calls Trump’s unconstitutional overreach.

“Preparing for and going to court with the law on our side and winning in court is important,” he said. “It is the most important thing that we can do legally.”

While Pritzker ruled out talk of a “soft secession” — a theory circulating among some Democrats about states withholding cooperation from the federal government — Trump signaled he may invoke the Insurrection Act to bypass governors’ objections.

“It’s been invoked before,” Trump told reporters in the Oval Office, referencing the 1807 law that allows a president to deploy troops to “suppress rebellion” when federal law enforcement becomes “impracticable.”

Legal experts note the law has been used about 30 times in U.S. history, most recently by President George H.W. Bush during the 1992 Los Angeles riots with the support of California’s governor. The last time it was used against a governor’s wishes was in 1965, when President Lyndon Johnson federalized troops in Alabama to protect civil rights marchers.

Pritzker has also joined California Gov. Gavin Newsom in threatening to leave the bipartisan National Governors Association (NGA), accusing it of failing to stand up to Trump’s use of the National Guard.

“Well, I’m somebody who likes to reach out and do things in a bipartisan fashion,” Pritzker said. “But not if [the NGA] is unwilling to stand up in this moment and speak on behalf of states’ rights the way that it always has.”

The governor defended his administration’s timing in filing a lawsuit to block the troop deployment, which came two days after Defense Secretary Pete Hegseth issued a memo authorizing it.

“You have to understand legal proceedings,” Pritzker said. “In order for you to bring a lawsuit of any sort, you have to have what’s called ripeness. It has to be ripe. That means there has to be some action that’s taken to demonstrate that the wrong is being effectuated.”

Calling any criticism of the timing “a false avenue to follow,” Pritzker made clear he intends to fight Trump’s actions in court — not on the streets.