Tensions between the Trump administration and California leaders are escalating into an all-out political war, as Gov. Jerry Brown and his allies vow to fight the president tooth-and-nail over everything from sanctuary cities to environmental policies.

President Trump fired the latest shot when he threatened to “defund” unspecified programs over California’s push to become a “sanctuary state.” In an interview with Fox News’ Bill O’Reilly, he criticized California lawmakers for pursuing a statewide law to limit local law enforcement from cooperating with federal immigration authorities.

“I think it’s ridiculous,” Trump said, adding that sanctuary cities “breed crime.” “We will certainly not stand for sanctuary even cities, let alone states.”

Calling California “out of control,” Trump described the threat of pulling funding as a White House “weapon.”

While using the federal purse as leverage might work in some states, Senate President Pro Tem Kevin de Leon said it doesn’t pack as strong of a punch in California.

“Far from being out of control, California is creating jobs faster than any other state and immigrants are key to our economic prosperity,” he said in a written statement. “We are an engine for the country’s innovation and job growth and our state annually pays more in federal taxes than it gets back. Our economy is the sixth largest in the world and thirteen percent of the country’s GDP.”

Assembly Speaker Anthony Rendon added, “If this is what Donald Trump thinks is ‘out of control,’ I’d suggest other states should be more like us.”

The statements gloss over California’s history of budget problems, poorly ranking public schools and ongoing struggle with high unemployment in some regions.

But ever since Trump’s election, Brown has set an adversarial tone with the new administration. Brown delivered a fiery rebuke against Trump in his January State of the State address, underscoring years of bitter conflict and foreshadowing even more.

“We’ve seen the bald assertion of ‘alternative facts,’ whatever those are,” Brown said. “We’ve heard the blatant attacks on science. Familiar signposts of our democracy — truth, civility, working together — have been obscured or even swept aside.”

The fourth-term Democratic governor is now pitching his state as an outpost of resistance against Trump and pointedly vowing to push back against efforts by the administration to reverse environmental policies.

"We've got the scientists, we've got the lawyers and we're ready to fight," he said during a December speech to the American Geophysical Union in San Francisco.

Brown also tried to soothe concerns that Trump might eliminate NASA’s Earth sciences department.

Nicknamed “Governor Moonbeam” by a newspaper columnist in 1976 for his interest in a state-sponsored satellite, Brown told the revved-up San Francisco crowd, “If Trump turns off the satellites, California will launch its own damn satellite.”

Trump has remained skeptical of science that says humans cause climate change, amid fears from the other side that his administration could stifle research on the subject. The official White House website wiped nearly all mention of climate change within minutes of Trump’s inauguration. The only reference to it is his vow to reverse what the Obama administration had done.

Trump also has had to contend with California criticism – from the public and private sectors – in the wake of his recent executive order on immigration. In a rare show of unity, Silicon Valley tech executives joined forces last weekend to file an amicus brief in the 9th Circuit Court of Appeals in San Francisco in support of a lawsuit against the order.

“Immigrants or their children founded more than 200 of the companies on the Fortune 500 list,” the brief states. “Collectively, these companies generate annual revenue of $4.2 trillion, and employ millions of Americans.”

Whether California, which voted overwhelmingly against Trump in November, can continue to go toe-to-toe with Trump is still up in the air.

The state recently had to shelve a controversial proposal that would have provided health insurance to undocumented immigrants under ObamaCare. California had been pursuing a waiver that would open up coverage through the state’s ObamaCare marketplace to 390,000 adult undocumented immigrants.

Brown signed on but the final approval depended on clearance from the administration. Brown and the bill’s sponsor Sen. Ricardo Lara withdrew the waiver citing fears that the Trump administration might go after residents who signed up.