() President Donald Trump and California Gov. Gavin Newsom’s often-hostile relationship is facing yet another public test amid anti-ICE protests in Los Angeles.

On Monday, Trump summarized their on and mostly off relationship with a single sentence: “Look, I like Gavin Newsom. He’s a nice guy. But he’s grossly incompetent.”

The pair have frequently clashed over policy, politics and personality, at times reconciling in times of need. But ongoing LA demonstrations have heated their relationship to a boiling point.

White House threatens to arrest Newsom as he sues Trump

Newsom and California’s attorney general have filed a lawsuit over Trump’s decision to send more than 4,000 California National Guard troops to Los Angeles despite no city or state officials requesting them.

The suit, filed in federal court in San Francisco on Monday, called the move an “unprecedented power grab.”

In a social media post Tuesday morning, Trump defended his decision to send federal forces to LA.

“If I didn’t ‘SEND IN THE TROOPS’ to Los Angeles the last three nights, that once beautiful and great City would be burning to the ground right now, much like 25,000 houses burned to the ground in L.A. do to an incompetent Governor and Mayor,” he wrote in part.

Newsom and other Democrats warn that the troops’ arrival only serves to escalate the situation.

The litigation comes after Trump’s border czar Tom Homan said he would arrest Newsom over his handling of the immigration enforcement protests.

Trump supported the idea, telling reporters, “I would do it if I were Tom.”

Newsom called the threat an “unmistakable step toward authoritarianism” in a post on X.

During an interview with MSNBC on Sunday, the governor prompted Homan and Trump to make good on their promise: “He’s a tough guy, why doesn’t he do that? He knows where to find me.”

Trump feud could fuel Newsom’s future

During his 2024 campaign, Trump often referred to the California governor not as Newsom but as “Newscum,” a nickname that positioned the duo as foils.

The pair’s most recent public feud could have the same or even more severe consequences, according to California State University, Long Beach political science professor Matt Lesenyie.

“Democrats are looking for who’s going to be the next fighter,” Lesenyie told USA Today.

If Newsom were to be arrested, it could secure his spot as the Democrats’ next “political star” who stands up to Trump, Sonoma State University political science professor David McCuan told the outlet.

Newsom fights Trump’s tariffs with litigation

In April, Newsom sued the Trump administration over sweeping tariffs enacted under the International Emergency Economic Powers Act.

Newsom, along with California Attorney General Rob Bonta, contended the tariffs have “disrupted” supply chains, hiked costs for Californians and damaged the state’s economy. 

“President Trump has overstepped his authority, and now families, businesses, and our ports are literally paying the price. As the largest economy in the nation, California has the most to lose from President Trump’s weak and reckless policies,” Newsom said in a press release.

Trump and his allies have vigorously defended his trade agenda, arguing the duties will lead to a manufacturing revival in the U.S. and help slash the nation’s growing deficit.

Trump blames Newsom for California wildfires, then cools down

During January’s devastating wildfires in Southern California, Trump pointed the finger at Newsom and Los Angeles Mayor Karen Bass and called for both their exits.

Trump argued that Newsom should have signed a declaration to pump more water through California to prevent the situation, despite state and federal conservation regulations preventing the Sacramento-San Joaquin Delta from doing so.

“Now the ultimate price is being paid. I will demand that this incompetent governor allow beautiful, clean, fresh water to FLOW INTO CALIFORNIA! He is the blame for this,” Trump said in social posts at the time. “On top of it all, no water for fire hydrants, not firefighting planes. A true disaster!”

Newsom denied he or Bass had anything to do with the city’s inability to tame the fires and bit back at Trump.

“People are literally fleeing,” Newsom said in early January. “People have lost their lives. Kids lost their schools, families completely torn asunder, churches burned down.”

“This guy wanted to politicize it,” he said. “I have a lot of thoughts, and I know what I wanna say. I won’t.”

Late January into February saw the forging of a makeshift truce between Trump and Newsom.

“I have all the expectations we’re going to be able to work together,” Newsom said. Trump responded, “We’re going to get it fixed.”

partner The Hill and The Associated Press contributed to this report.