LOS ANGELES — California conservatives are feeling a strange sense of invigoration these days. Yes, they are vastly outnumbered, shouted off college campuses and scolded that their way of politics is an anachronism in this bright blue bulwark of the liberal resistance.

But California has become, however improbably, a leading exporter of the energy that is animating the conservative movement, and it is giving rise to some of the loudest new voices on the right, from the West Wing to the radical fringe.

Some of the most strident conservatives in President Trump’s orbit have honed and hardened their political identities in California. There is Stephen K. Bannon, the president’s ousted but still influential chief strategist, who was showered with standing ovations when he spoke at the state Republican convention in Anaheim last weekend. And there is Stephen Miller, a senior White House adviser from Santa Monica who has helped shape the White House’s restrictive immigration policy.

Several of the most aggressively pro-Trump media outlets and personalities, which provide a critical line of support between the president and his base, are based in California, like Mr. Bannon’s nationalist-oriented Breitbart News and Michael Savage, a radio host who has raised the specter of civil war if Mr. Trump is removed from office. Two of the far-right’s best-known pro-Trump conspiracy theory peddlers, Mike Cernovich and Charles C. Johnson, work from California.

And California is home to some of the most Trump-friendly academics, who have made the intellectual case for the president’s agenda in scholarly publications like the Claremont Review of Books. Last fall the review published a widely read essay by Michael Anton, a native Californian and national security aide in the Trump administration, who argued that a Hillary Clinton presidency would be like “Russian Roulette with a semi-auto.”

“It’s almost an inverse proportion: The less powerful we got in California, the more powerful we got nationally,” said Ben Shapiro, a writer and commentator from Southern California. Mr. Shapiro founded the Daily Wire, a right-leaning website that he helps run out of an office in the Sherman Oaks neighborhood of the San Fernando Valley.

“California’s Republican Party is largely moribund, but a lot of California is the intellectual center for the Republican Party,” Mr. Shapiro added, offering one possible explanation for the disconnect. “When you’re not in governance, that allows you to be a little more creative in the ideas you espouse.”

Republicans are shut out of statewide office here, and have been for most of this decade. Twenty-five years ago, they made up almost 40 percent of the state’s registered voters; today, they are barely 25 percent. In many races, they don’t even appear on the ballot any more, because the state’s primary system allows the two top vote-getters to advance to the general election regardless of party affiliation, and they are often both Democrats.

And few states have done more to try to thwart President Trump’s agenda on issues like the environment and immigration.

Still, some conservatives see a cautionary tale in California, where the Republican Party sank into political irrelevance in recent years as it became defined by an unyielding line on immigration, an enthusiastic embrace of the culture wars and a willingness to exploit racial divisions. It was only ten years ago that California had a centrist Republican governor in Arnold Schwarzenegger. And even though a larger share of voters than ever are registering with no party affiliation, Republicans remain woefully uncompetitive in the state.

“By all accounts, there should be this sort of vibrant center-right movement in California that’s contesting those voters,” said Lanhee Chen, a fellow at the Hoover Institution who advises Republican candidates and grew up in the Los Angeles area. “But you’re really not seeing that.”

The issues now stoking the conservative populism that has taken over the Republican Party — political correctness, affirmative action, the flight of blue-collar jobs overseas, illegal immigration and government bloat — simmered in California for decades before Mr. Trump rode them to the White House.

The ardently anti-communist, aggressively nationalist John Birch Society developed one of its largest followings in Orange County in the 1960s. The fight over Proposition 13 in the late 1970s, which limited property-tax increases, became a national cause for anti-tax, anti-government conservatives. And in the 1990s, California voters approved ballot initiatives intended to strike blows against the liberalism of the Clinton era by banning affirmative-action policies at state institutions and by preventing undocumented immigrants from having access to public services like schools and hospitals.

Because California was at the forefront of the demographic changes reshaping the country’s politics, the questions now dividing the national Republican Party hit California much earlier. That would give Republicans a preview of the debate now raging over the future of their party today: whether to double down on nationalism or take a more accommodating approach to immigration.

“That blowback to liberalism and the Republican establishment develops in California,” said Lawrence Rosenthal, director of the Center for Right Wing Studies at the University of California, Berkeley. “And I think it’s not a surprise that it develops in California, because of what happened in California with the arrival of a majority minority.”

He added: “California was at once the poster child for changing demography; the poster child for the Republican establishment saying, ‘We have to have an opening on immigration or we’ll become a regional party’; and the poster child for this more extreme nationalist ideology.”

In Pete Wilson, a Republican former governor, many people see an early template for Mr. Trump. Mr. Wilson championed Proposition 187, the 1994 measure that would have cut off public services for undocumented immigrants and that became a national rallying cry on both the right and the left. (Though it passed with 59 percent of the vote, Proposition 187 was blocked by a federal court and never went into effect.)

Mr. Wilson remains unapologetic, and said he was convinced that Mr. Trump understands what he did back then, and how confronting illegal immigration spoke powerfully to disaffected conservatives.

“Trump, however he divined this, was talking about these things, and a lot of people who should have been weren’t,” Mr. Wilson said in an interview from his law office on the 28th floor of a high rise in Century City. Mr. Wilson, who said he voted for Trump enthusiastically — “Hell yes” — regrets only the way Proposition 187 became to be perceived.

“It convinced a number of Latino Californians that they were living in a place run by bigots, because that’s the way it was portrayed. And it made a lot of Republican politicians gun-shy.”

The reaction to the initiative certainly caused many Republicans to rethink a hard-right position on immigration. But it emboldened others.

“There’s a rebellious tone to conservatism in California that doesn’t exist in places where conservatism is actually a governing force,” said Mr. Shapiro, who is a former editor for Breitbart News. Andrew Breitbart, the site’s founder, grew up in Los Angeles, where the community of conservatives is small enough that he eventually found himself in the company of people like Mr. Shapiro, whose writing as a student for the University of California Los Angeles caught his eye. Mr. Breitbart also grew close to Mr. Bannon, who was working in Hollywood as a producer of right-wing documentaries when they became friends.

Mr. Breitbart died in 2011, but much of the site and its business operations are still run out of offices on the West Side of the city. Joel Pollak, the editor at large, often writes about California politics — one recent article typical of the site’s coverage bore the headline, “Christopher Columbus Statue Fenced Off on L.A.’s 1st ‘Indigenous Peoples Day’ ” — and he said he considers his assignment for Breitbart readers to be “like a foreign correspondent, telling them what life is like here.”

For conservatives, he said, “liberal California has become a political and cultural crucible.”

California has also become a battleground in the resistance to “the resistance,” the informal liberal opposition to Mr. Trump. Right-wing speakers like Ann Coulter, Milo Yiannopoulos and Mr. Shapiro have all chosen the deeply liberal campus of the University of California at Berkeley as a place to speak, despite the threat of violence from leftist demonstrators. And they point to the way they are shunned on campus — both Ms. Coulter and Mr. Yiannopoulos had to cancel their planned speeches, and nine people were arrested outside the hall where Mr. Shapiro spoke last month — as examples of left-wing thought-policing.

In August, liberal Angelenos were outraged when the Santa Monica Symphony Orchestra invited Dennis Prager, a conservative writer and radio host based in Los Angeles, to be a guest conductor. Seven symphony members said they would refuse to play under his direction.

But the uproar made Mr. Prager, a classical music aficionado who has argued that Mr. Trump’s election “may have saved the country,” into a cause célèbre on the right. The event sold out.