President Trump today plans to revoke California’s landmark emissions standards, setting up another sweeping legal fight with the nation’s largest state that may echo beyond his presidency.

Why it matters: Trump is at war with California over the environment, homelessness, tax returns, immigration and virtually every topic he touches. The courts are almost always center stage.

Gov. Gavin Newsom (D) — who earlier this year told "Axios on HBO" that Trump is helping turn the GOP into a dying, xenophobic party — accused the president of a "political vendetta" with his latest move.

This could snuff out any hope automakers had of avoiding a bitter legal fight between the administration and California, Axios' Ben Geman writes.

"This will be the biggest fight in environmental law since the Clean Power Plan. Maybe bigger," tweeted Nathan Richardson of the University of South Carolina School of Law.

The backdrop: Trump, who spent the night in L.A., kicked off a Golden State moneymaking swing yesterday with a $3 million Bay Area luncheon, followed by a $5 million Beverly Hills dinner at the home of real estate developer Geoffrey Palmer, per AP.

Trump will bring in $7 million today with a breakfast in L.A. and luncheon in San Diego, before he visits the border wall.

The bottom line: The landscape on California issues would shift overnight if a Democrat wins the White House — but Trump rightly sees the state as unwinnable.

Go deeper: California plays by its own rules