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Gov. Gavin Newsom had a fleeting win against President Trump last week when a federal judge handed down an order that would have halted Trump’s deployment of the National Guard in Los Angeles. Within hours of that decision, the 9th Circuit Court of Appeals suspended the ruling, allowing the troops to remain under Trump’s control.

Today, the appeals court is scheduled to pick up where it left off in Newsom’s challenge to Trump’s order.

The narrow focus of the hearing — and the expected order from the judges sometime this week — has massive implications for California. Namely: Can Newsom reclaim command of the National Guard against Trump’s wishes?

The tenor of the legal arguments is fierce, mirroring the growing intensity in the quickly devolving relations between Trump and Newsom.

Last week, Newsom likened Trump to “failed dictators.” Trump’s legal team’s arguments “are terrifying,” Newsom’s team wrote to the panel of judges overseeing the hearing today.

On Sunday, Trump denounced “radical left Democrats as “sick of mind” who “hate our country” on social media. “We must expand efforts to detain and deport Illegal Aliens in America’s largest Cities, such as Los Angeles, Chicago, and New York, where Millions upon Millions of Illegal Aliens reside,” he declared.

The arguments will play out in front of a three-judge panel, two of whom were appointed by Trump and one by former President Joe Biden, a Democrat.

This isn’t the only hearing that’ll determine who gets control of the 4,000 guard members Trump deployed since June 7, after protests in the Los Angeles area erupted in response to federal immigration officers raiding work sites and arresting individuals they say are in the U.S. without authorization. Those protests were in full force over the weekend.

On Friday, the lower court judge who initially sided with Newsom’s lawyers is expected to hold a hearing on whether to issue a preliminary injunction blocking Trump’s deployment of military personnel, including the Guard, to Los Angeles. For Newsom’s legal team to prevail in that hearing, they’ll have to clear a higher threshold of scrutiny. That’s because anyone seeking a preliminary injunction must demonstrate that the merits of their arguments will likely prevail in the full trial.

But while the hearings this week and last are occurring before different judges in different courts, the arguments are similar. Trump’s team says there’s rebellion in the streets. Newsom’s team says local police can handle protesters and that sending in federal forces further inflames tensions.

Trump’s lawyers say this isn’t even a subject the courts can weigh in on, since the president has full discretion on when to use the military. Newsom’s lawyers — and the lower court judge, Charles Breyer — say “that argument fails.”

The attorneys from the U.S. Department of Justice who are representing Trump have so far argued that the president was in his right to order the National Guard under the law that he cited last Saturday. Trump wrote last week that “incidents of violence and disorder” occurred in L.A. in his message to call up the National Guard. His lawyers continue to maintain that the Los Angeles protesters represented “a rebellion or danger of a rebellion against the authority” of the U.S. government — the very language in the law that permits a president to federalize a state’s National Guard.

Much of this week’s hearings rests on what powers the president has under that specific federal law. But Trump hasn’t invoked the full suite of his legal powers to send in the military to California. That would mean triggering the Insurrection Act, which would permit the armed forces to act as law enforcement. Presently, the National Guard is supposed to protect federal property and officers.

That’s why Newsom’s legal team tossed in a footnote in their argument to the appeals court that even if the National Guard isn’t returned to Newsom’s control, Trump should still be blocked from having the Guard perform “law-enforcement activities beyond the protection of federal buildings and personnel at those facilities.”

The White House legal team also argues that contrary to what Newsom’s team says, a president under this federal law doesn’t need the formal approval of a state governor to call up the National Guard.

Lawyers from the California’s Department of Justice who are representing Newsom argue that only once before has a president invoked this law to call up the National Guard; President Richard Nixon did so in 1970 to deliver the mail during a U.S. Postal Service strike.

The National Guard in the Nixon era stepped in to effectively replace the 200,000 workers who were withholding their labor. But in Los Angeles, thousands of law enforcement from local and county agencies patrolled the streets during the protests and arrested hundreds of people, Newsom’s lawyers wrote. There’s no shortage of law enforcement to quell the pockets of unrest in Los Angeles, they wrote.

According to a Trump filing, “the crowd of protestors outside the federal building on June 6 that prompted the initial federalization order …had fully dispersed within about four hours of LAPD’s arrival,” Newsom’s legal team wrote in a filing Sunday.

“As the district court found based on the record evidence, the circumstances here do not remotely amount to a ‘rebellion or danger of a rebellion,’” Newsom’s legal team wrote.