Just a few short days ago, President Trump was remarkably and viciously feuding with Elon Musk, the world’s richest man and the person who spent more money than anyone to return him to the White House.

But one of the constants in Trump’s second term is that the subjects of his quarrels are ever-changing. And by Monday, Trump had turned the page on Musk — for now — and focused on a more familiar and frequent target for his rage: Gavin Newsom, the Democratic governor of California.

This was, as my colleague Tyler Pager wrote, the fight that Trump had been waiting for, and on an issue that is perhaps most central to his political identity: cracking down on immigration.

Over the weekend, Trump moved to take control of California’s National Guard and deployed troops where protesters had clashed in Los Angeles with federal law enforcement officers over immigration raids.

Newsom and other California leaders, including Mayor Karen Bass of Los Angeles, accused the president of fanning the flames and needlessly escalating matters rather than calming them. This morning, the state announced plans to sue Trump for his deployment of the Guard.

“These are images that Donald Trump created,” Newsom said in a local television interview, referring to the unrest, burning cars and police clashes. “Of course he wants it politically.”