President Donald Trump turned up the heat this weekend on the country’s most populous state, calling California “out of control” and soft on immigrants.

He vowed to cut funding to California if officials vote to declare it a sanctuary state for undocumented immigrants, and warned that California and his administration are on a “collision course.”

California “is, as you know, out of control in many ways,” Trump told Fox News host Bill O’Reilly in an interview aired Sunday before the Super Bowl.

A state Senate committee last Tuesday approved a bill that would prohibit all local law enforcement agencies from using resources to enforce federal immigration laws. Los Angeles, Sacramento and San Francisco are already sanctuary cities.

“I think it’s ridiculous. Sanctuary cities, as you know, I’m very much opposed to sanctuary cities. They breed crime, there’s a lot of problems,” Trump said.

The president said he doesn’t “want to defund the state or city” ― but “if they’re going to have sanctuary cities, we may have to do that. Certainly that would be a weapon.”

“If we have to, we’ll defund,” Trump went on. “We give tremendous amounts of money to California.”

In fact, California, which has the eighth largest economy in the world, receives approximately 78 cents for every dollar it pays the feds, according to the most recent analysis available by the Tax Foundation, a nonprofit think tank. A recent survey found that California is the fifth least dependent state in the nation on federal funds. In an interview last month, Lt. Gov. Gavin Newsom (D) said that the U.S. “needs California more... than California needs it from an economic perspective. California is the economic engine of the country.” (He also called Trump’s plans to build a wall on the U.S.-Mexico border “laughable.”)

But the University of California system would be vulnerable to federal funding reductions that would have to be made up by state money in the event of a cut. It receives at least $9 billion a year in grants, financial aid and research funds. Trump threatened to cut funds after violent protests at the University of California, Berkeley, in early February forced the cancellation of a speech on campus by the right-wing agitator Milo Yiannopoulos.

If U.C. Berkeley does not allow free speech and practices violence on innocent people with a different point of view - NO FEDERAL FUNDS? — Donald J. Trump (@realDonaldTrump) February 2, 2017

Trump insisted to O’Reilly that California voters “obviously” agree with his anti-sanctuary stance. “Otherwise,” he said, “they wouldn’t have voted for me.”

In fact, California, home to 39 million people, voted overwhelmingly for Hillary Clinton in the presidential election (62 percent to Trump’s 32 percent).

Trump has claimed that illegal votes in California cost him a popular vote victory — though he hasn’t offered any evidence for that claim, and none seems to exist.

CA ballots are now all counted. Unofficial results posted online show Hillary Clinton votes almost doubled those for President-elect Trump. pic.twitter.com/uPgIMqB58T — John Myers (@johnmyers) December 8, 2016

California officials have vowed to defy Trump’s policies not only on immigration, but also against any reduction in environmental protections. The state has placed on retainer former U.S. Attorney Eric Holder to battle the Trump administration in court.

Meanwhile, California Gov. Jerry Brown (D) is working with representatives to design a budget with some protections for federal funding cuts. He pledged in his State of the State address last month to defend “everybody — every man, woman and child — who has come here for a better life and has contributed to the well-being of our state.”