Can California leave the United States? What you need to know about secession

Explainer - One of last year's big movies was Civil War, a gritty look at an America torn apart by conflict into separate territories.

Fiction, right? But talk of seceding from the rest of the country is a very real hot topic in certain parts of California during the second presidential term of Donald Trump.

When Trump ordered the National Guard and US Marines into Los Angeles to tackle protests over his administration's immigration crackdown, that talk became a roar in some circles.

Some people said it was time for California - a frequently left-leaning, progressive state where Trump got only 38 percent of the vote in last year's election - to leave the United States of America entirely.

But could California actually leave the US, which it's been part of for 175 years? Here's what you need to know about secession.

Why are California and President Trump fighting?

Republican Trump and California Governor Gavin Newsom, a Democrat, have clashed for some time, but recent protests in Los Angeles over Trump's aggressive efforts to deport migrants have taken it to a new level.

Trump ordered in the National Guard to quell protests - a task that is usually the responsibility of governors and has resulted in a lawsuit by Newsom and California against Trump's administration. Trump then upped the ante more by also deploying US Marines.

He also appeared to endorse the unprecedented idea of having Newsom arrested if he defied Trump's orders.

The President of the United States just called for the arrest of a sitting Governor.

This is a day I hoped I would never see in America.

I don’t care if you’re a Democrat or a Republican this is a line we cannot cross as a nation — this is an unmistakable step toward… pic.twitter.com/tsTX1nrHAu

— Gavin Newsom (@GavinNewsom) June 9, 2025

Since his inauguration in January for a second term as President, Trump has broadly expanded presidential powers and cracked down on dissent.

Last week, CNN reported that Trump has looked at cancelling much of California's federal funding.

However, Trump may be the President, but Newsom is still the twice-elected leader of America's most populated state with nearly 40 million people.

California has economic muscle on its side. It's the fifth largest economy in the world with a GDP of nearly US$3.9 trillion as of 2023 - larger than India, the United Kingdom and France. If California did split away - and that's a very big if - it would instantly become one of the world's economic superpowers.

But can a state actually leave America?

"No, the US Constitution does not provide for a state to peacefully secede," University of Otago international relations professor Robert Patman said.

Still, clashes between the federal government and the rights of states have been a thread all through American history.

The last - and only - time secession happened, there was a bloody Civil War. In the climax of a long-brewing conflict over the existence of legalised slavery of Black Americans, 11 states seceded from the rest of the country. The four-year struggle from 1861 to 1865 left nearly 700,000 Americans dead and remains the single deadliest war in the nation's history.

There have always been secession and split movements brewing in parts of the United States. None of them have actually gotten very far.

For instance, in California, for years there's been scattered talk of splitting the rural far north of the state and parts of southern Oregon into a new "State of Jefferson."

In the heightened environment of the Trump years, talk of dividing up the country by political factions has grown louder.

"Growing political polarisation between 'blue' and 'red' states in the US poses a significant threat to its stability and democratic institutions," Patman said.

"The conditions that led to an attempted insurrection on 6 January 2021 in the US have not yet moderated and so further outbreaks of instability cannot be ruled out."

Georgia Republican Congresswoman Marjorie Taylor Greene called in 2023 for a "national divorce" between so-called red (Republican-leaning) and blue (Democrat) states. A 2021 poll by the University of Virginia Center for Politics found 52 percent of Trump voters and 41 percent of Biden voters at least somewhat agreed that they favoured blue and red states seceding from the union to form their own separate country.

And in January, a poll conducted by YouGov for the pro-secession group the Independent California Institute found that 61 percent of Californians polled said California would be better off if it peacefully seceded.

What's the legal basis for secession?

Pretty slim. California's own state constitution clearly says in Article III, Section 1 that "The State of California is an inseparable part of the United States of America, and the United States Constitution is the supreme law of the land."

Meanwhile, the US Constitution has no mechanisms within it to allow secession at all.

Back in 1869, shortly after the US Civil War, the Supreme Court ruled in the case of Texas V. White that states do not actually have the right to unilaterally secede and that the union was "perpetual": "There was no place for reconsideration or revocation, except through revolution or through consent of the States."

That precedent has pretty much remained ever since. Some say that could mean that all states might have to concede to one state's secession, or the Constitution itself would need to be amended, a long and complicated process. The late Supreme Court Justice Antonin Scalia wrote in a letter in 2010, "If there was any constitutional issue resolved by the Civil War, it is that there is no right to secede."

It's theoretically possible a state could just declare itself independent and devil take the consequences, but again, last time that happened hundreds of thousands died in civil war.

"The possibility of a second US Civil War is a serious concern, with surveys showing a significant number of Americans worrying about such a prospect," Patman said, noting that while the issues are quite different from the 1860s, many factors are fuelling division.

"These include the rise of far-right extremism, growing economic inequality, cultural conflicts, and the divisive impact of the social media."

Still, some people are already trying to do the California split

A movement called "CalExit" is hoping to put a measure on the ballot for California to vote on in November 2028 which would ask, "Should California leave the United States and become a free and independent country?

CalExit organiser Marcus Ruiz Evans has been trying to get secession on the table for years.

"Californians are aware they just don't think like Americans," he told RNZ's Saturday Morning in an interview in 2018 during Trump's first term.

"You know, the average American is not sure if climate change is real, questions if immigration is a good idea, wants to have massive amounts of guns and hates any regulations against them and is generally distrustful of government."

Organisers would need to get 546,000 signatures to put Ruiz Evans' latest measure on the ballot. To pass, 50 percent of registered voters must participate in the election and at least 55 percent of them would then have to say yes.

That doesn't mean that CalExit then becomes a thing. Instead organisers say "it would constitute 'a vote of no confidence in the United States of America' and 'expression of the will of the people of California' to become an independent country, but would not change California's current government or relationship with the United States".

If the ballot measure is approved, a 20-member commission would then evaluate the feasibility of California becoming an independent nation. However, there would be a long road to any actual change, and the courts might well put a stop to it.

"Even if this [ballot measure] passes, there's virtually no way it can result in California leaving the union," David A. Carrillo, director of the California Constitution Center at UC Berkeley Law School, told ABC News 10.

And civil war? That's not really likely either when the world is far more interconnected than it was in the 1860s.

"Any internal conflict in the US would generate global shockwaves and thus there would be much greater international resistance and perhaps intervention to prevent another civil war occurring," Patman said.

But still, secession talk isn't likely to go away anytime soon with America's politics seemingly stuck at a perpetual boiling point.

"We think we've gotten to the point where it doesn't work," Ruiz Evans told CBS News recently. "There are people out there who will respond to California as a nation."

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