Judge Charles Breyer’s opinion echoed remarks he made during a 3-day trial in which he questioned if presidents have any limits on when they can use the military.

A judge on Tuesday found that President Donald Trump acted unlawfully when he activated thousands of National Guard members and deployed a handful of Marines to address anti-Immigration and Customs Enforcement riots and protests in California.

Judge Charles Breyer said Trump, as well as Secretary of Defense Pete Hegseth, violated the Posse Comitatus Act, a 150-year-old law that says the military cannot typically engage in domestic law enforcement.

Breyer, a Clinton appointee, blocked Trump and Hegseth from using the military in a way that violates the Posse Comitatus Act. He noted violations could include conducting riot control, making arrests and setting up traffic stops.

The judge said his order only applies to California, but he noted the administration’s warnings about sending the National Guard to other blue cities across the country amount to “creating a national police force with the President as its chief.”

Breyer’s opinion echoed remarks he made during a three-day trial last month when he questioned if presidents have any limits on when they can use the military for domestic purposes.

“I go back to the thing that I’m really troubled by: What limiting factors are there to the use of this force?” Breyer asked during the trial.

Trump federalized about 4,000 National Guard members and deployed 700 Marines in June to support federal authorities in California as they carried out immigration raids, despite Democratic Gov. Gavin Newsom’s vehement objections.

Breyer’s decision comes as most of the troops have since been demobilized. Attorneys for California said during the trial, though, that 300 National Guard members remained, which they argued was a “significant” number.

“That’s certainly a large enough number of soldiers to constitute a Posse Comitatus Act violation,” a state attorney said.

Newsom celebrated the order in a statement on social media, saying Trump “LOSES AGAIN.”

“The courts agree — his militarization of our streets and use of the military against US citizens is ILLEGAL,” Newsom wrote.

While the judge’s decision may have minimal impact on the ground in California, the case could still have nationwide implications as Trump and Hegseth deploy National Guard members in Washington, D.C., and threaten to do so in other blue cities, including Chicago, to address street crime.

The Trump Department of Justice is able to appeal Breyer’s decision, which could result in the U.S. Court of Appeals for the Ninth Circuit and even the Supreme Court weighing in on the administration’s unconventional use of the National Guard.

One witness during the trial, Major General Scott Sherman, who oversaw National Guard activity in California, testified that soldiers were trained on how to stay in compliance with the Posse Comitatus Act, which Breyer said was evidence that it was relevant to the lawsuit. The Trump administration had argued the law was not applicable in the case.

The judge’s decision comes after the Ninth Circuit quickly halted an emergency order Breyer issued in June in which he ordered Trump and Hegseth to hand control of the National Guard back to Newsom.

The courts must be “highly deferential” to the president when reviewing his deployment of the National Guard, the appellate court found at the time. The same court is now likely to weigh in on Breyer’s new, narrower ruling.