PORTLAND, Ore. — A federal judge Saturday blocked the Trump administration from using Oregon National Guard soldiers to help quell nightly protests at an Immigration and Customs Enforcement building in Portland, Oregon.

Judge Karin Immergut, of U.S. District Court in Oregon, sided with Democrats who run the state government when she issued a temporary restraining order blocking the mobilization. President Donald Trump and the Defense Department had ordered 200 Oregon soldiers for a 60-day deployment.

In her ruling, Immergut wrote that she expected a trial court to agree with the state’s contention that the president exceeded his constitutional authority in mobilizing federal troops for local work and likely violated the 10th Amendment.

The soldiers have been training on the Oregon coast and were expected to be in place by the weekend, though federal officials have not said what duties they would perform beyond assisting ICE. Immergut’s ruling expires Oct. 18, and federal lawyers indicated in court that they planned to appeal if the temporary restraining order was granted. The restraining order is part of a larger lawsuit filed by Oregon and Portland against the administration.

During almost two hours of arguments Friday, lawyers for Oregon’s attorney general, Dan Rayfield, contended that the president did not have the authority to use the National Guard at the ICE facility and warned that the arrival of federal forces would lead to greater violence.

State and city attorneys described Trump’s selection of Portland for deployment as “at best, arbitrary, and at worst, a politically motivated retaliation for the adoption of policies” that the president viewed as too liberal.

The president’s actions “represent one of the most dramatic infringements on state sovereignty in Oregon’s history,” Scott Kennedy, an attorney for Oregon, said in court.

“They radically reshape the balance of federal-state power,”

State lawyers also questioned the timing of Trump’s decision, noting records from the Portland Police Bureau that showed the size of the nightly demonstrations had dwindled before the president posted on his social media website last Saturday that he planned to ask the Department of Defense to use federal troops to “protect” Portland.

Portland police commanders checked in with ICE officials every evening, according to records they filed in support of the temporary restraining order, and for several weeks prior to the president’s declaration, ICE employees reported that things were relatively quiet and that they did not need help.

Immergut, who was appointed by Trump during his first term, agreed that the timing of the president’s order did not meet the legal standard for calling in the National Guard, saying the state provided “substantial evidence that the protests at the Portland ICE facility were not significantly violent or disruptive in the days — or even weeks — leading up to the president’s directive.”

Kennedy also said the situation in Portland did not meet the standard required for mobilization of federal soldiers for domestic work; the law allows federal troops to be used domestically in times of foreign invasion, rebellion or when normal law enforcement efforts are not capable of maintaining order.

Federal lawyers contended that the protests in Portland constituted both a potential rebellion and a law enforcement challenge beyond what federal officers on the ground could handle. But Kennedy said the federal government was defining “rebellion” so broadly it could include any political demonstrations or “opposition to its authority.”

Immergut agreed, writing that the federal government had shown evidence of “sporadic violence” but not “any evidence demonstrating that those episodes of violence were part of an organized attempt to overthrow the government as a whole.”

Eric Hamilton, a Justice Department lawyer, told the judge the decision to use National Guard soldiers was prompted by the Sept. 24 shooting that killed two detainees at a Dallas ICE facility and months of demonstrations in Portland that have left federal employees frightened and exhausted.

“Violent and cruel radicals have laid siege,” he said. “The evidence we have submitted at least reflects a danger of a rebellion, monthslong targeting of the Portland ICE building with violence, intimidation and threats.”

In the order released Saturday evening, Immergut wrote that the president’s argument about the need for mobilization was contradicted by evidence that recent protests had been comparatively quiet and nonviolent,.