A federal judge ruled that Donald Trump illegally deployed the national guard against protesters in Los Angeles and ordered the US government to return control of the troops to California.

The US district judge, Charles Breyer, issued a temporary restraining order against the Trump administration on Thursday, saying the president had overstepped his authority by taking control of the national guard to quell demonstrations against immigration raids in LA.

The order goes into effect on Friday at noon, with the judge saying the president had violated the 10th amendment, as the state of California had argued.

The justice department argued at a roughly hourlong hearing today that under the Title 10 statute invoked by Trump, the US president had the power to decide whether the protests had escalated and required the national guard to quell a “rebellion or a danger of rebellion”.

But Breyer said that the statute was not structured in a way that suggested Trump would have the power to be the sole determiner of whether such conditions had been met.

“If the president had complete discretion, why wouldn’t it say: ‘Whenever the president thought’ or ‘if the president agrees’ or ‘in the sole discretion of the president, he finds one, two and three’,” Breyer said to the justice department during a hearing. “They don’t say any of that.”

Although the protests have generally been peaceful with the exceptions of pockets that turned violent, the justice department contended Trump’s absolute discretion meant his underlying basis for his decisions could not be reviewed by federal courts.

The judge appeared particularly incredulous at the notion there could be no judicial review. “If the president finds there to be a rebellion, then it is a rebellion,” Breyer said with his voice sharply rising in intonation. “How is that any different to what a monarchist does?”

The lawyer for the California governor, Gavin Newsom, who filed the request for an injunction, argued mobilizing the guard was a power delegated by Congress – meaning it was not an inherent power of the president that made his decisions unreviewable.

“They are saying that the president, by fiat, can federalize the national guard and deploy it in the streets of a civilian city whenever he perceives that there is disobedience to an order,” Nicholas Green told the judge.

The request for the injunction is part of a lawsuit filed by the state of California challenging Trump’s move to call up more than 4,000 national guard troops and about 700 active-duty marines based in Twentynine Palms, California, over Newsom’s objections.

The complaint argued there was no basis to call in the national guard because the protests did not rise to the level of rebellion, and that the Trump administration did not satisfy the procedural requirement to consult with the governor to federalize the state’s national guard.

The justice department said they interpreted the statute to mean Trump’s order had to be logistically “passed through” the governor and that in this case, it had notified the adjutant general of the California national guard, to which Newsom had delegated authority.

Trump has been suggesting the idea of deploying troops against Americans since his first term, when some Black Lives Matter protests in the summer of 2020 turned violent. He opted against doing so at the time, but has since expressed regret to advisers that he did not punish the protesters more aggressively.

Notably, during a campaign rally in 2023, Trump vowed to respond more forcefully if elected to a second term. “You’re supposed to not be involved in that, you just have to be asked by the governor or the mayor to come in,” he said of the president’s usual role in deciding whether to send in the military. “The next time, I’m not waiting.”

The Associated Press contributed reporting