President Trump’s power going forward to deploy the National Guard to Democratic-contolled cities that object to the plan could hinge on what judges decide is the definition of a rebellion. Lawyers for the Trump administration argued in two courts on Thursday that the president has the authority to deploy those troops to Portland and Chicago.

In one of the cases, a three-judge panel for the United States Appeals Court for the Ninth Circuit at San Francisco is being asked to overturn a lower court order that blocks the troop deployment in Oregon.

A United States District Court judge, Karin Immergut, issued a temporary restraining order on Saturday to halt Mr. Trump’s deployment of the National Guard at Portland.

Mr. Trump has characterized Portland as “war-ravaged” and “under siege” because of ongoing nightly demonstrations against Immigration and Customs Enforcement, saying the National Guard is needed to protect the ICE agents. In June, violent protests forced the ICE facility at Portland to close for several weeks.

Oregon officials have resisted the deployment, calling it unnecessary and saying it will only raise tensions in the community.

The judges pressed a Trump administration lawyer, Eric McArthur, to define rebellion in the context of deploying federal troops. Mr. McArthur cited the violence directed at ICE agents at the Portland facility, calling the situation “unsustainable and unsafe.”

The senior assistant attorney general for Oregon, Stacy Chaffin, said a rebellion needs to include the element of people attempting to overthrow the government. 

One of the Ninth Circuit judges appeared ready to overturn the temporary injunction blocking the troop deployment. Judge Ryan Nelson questioned the lower court ruling, calling its analysis “wrong.”

“I’m sort of trying to figure out how a district court of any nature is supposed to get in and question whether the president’s assessment of executing the laws is right or wrong,” Judge Nelson, one of two Trump appointees on the panel hearing the appeal, said.

“It may well be that the forces are used in an improper way, but we don’t have any evidence of that right now. All we have is a document that says, ‘We have a federal facility under attack where violence has forced it to close down, and we want to protect it,'” Judge Nelson told Ms. Chaffin. “That doesn’t strike me as a glaring overuse on its face.”

The judges didn’t immediately issue a ruling in the case. The Ninth Circuit previously ruled in favor of Mr. Trump in another case involving the National Guard. In June, a panel of judges ruled the president could retain control of California’s National Guard after he called them up to quell unrest in Los Angeles over the objections of Governor Gavin Newsom.

The second hearing was held at Chicago regarding a lawsuit by the city and Illinois to temporarily block the troop deployment in the Chicago area. Mr. Trump has portrayed the Windy City as a lawless “hellhole” of crime, but local officials say the troops are not needed.

“There is no rebellion in Illinois,” a lawyer from the Illinois attorney general’s office, Christopher Wells, said. Mr. Wells added that the deployment was “illegal and lawless.”

A Trump administration lawyer, Eric Hamilton, said that there doesn’t need to be a rebellion for the president to deploy the troops. He told Judge April Perry that Mr. Trump’s decision to send in the National Guard was “unreviewable” and was needed to respond to an urgent threat to the safety of federal officers.