Californians looking to vote for a Republican in the June 5 governor’s primary face largely the same choice they have for the past decade: a tough-talking conservative officeholder or a wealthy businessperson who has never been elected.

In 2010, the choice was between then-state Insurance Commissioner Steve Poizner and billionaire former eBay CEO Meg Whitman. In 2014, the options were Tea Party favorite Assemblyman Tim Donnelly and former Goldman Sachs Vice President Neel Kashkari.

Both times, the wealthy businessperson advanced to the general election, to be crushed by Democrat Jerry Brown.

This year, the choice is between Assemblyman Travis Allen, R-Huntington Beach (Orange County), who portrays himself as the true fan of President Trump in the race, and businessman John Cox, who says he voted for a third-party candidate for president in 2016 — yet won Trump’s endorsement Friday anyway. With far fewer registered Republicans than Democrats in California, it’s likely that only one of the GOP gubernatorial candidates, at most, will finish in the top two in the primary and advance to November.

Republican officials say a top-two finish is crucial, not so much because of the possibility the GOP could win in November — no Republican has won a statewide office since 2006 — as because the party needs to give conservatives a reason to bother to vote. Republicans are playing defense in several of their congressional seats in California and need a motivated base to fend off Democrats hoping to flip 23 seats nationally and win back the House.

So in a way, the choices Californians make for governor in a little more than two weeks could determine who controls the House for the next two years. For Republicans, the choices couldn’t be more different in style than Allen and Cox.

Travis Allen

Allen’s political awakening happened about eight years ago when he began attending political fundraisers — for Democrats. He wasn’t a candidate then. He was, and still is, a certified financial planner in Orange County.

But clients and his uncle Frank Barbaro, then-chairman of the Democratic Party of Orange County, invited him to fundraisers. So he went to a $1,000-a-head event for Brown and a $100-apiece benefit for his now-opponent in the governor’s race, Lt. Gov. Gavin Newsom.

Allen says those fundraisers “galvanized” him — but not in the way the Democrats intended. He says he heard nothing that acknowledged that the state where he’d lived his whole life was deteriorating, and why those close to him were moving away.

His parents couldn’t afford to retire in a coastal community to their liking, so they moved to Oregon. His best friend decamped to Texas and a home twice as big. Business clients scattered to 20 different states.

When he grew up, Allen said, California’s public schools, roads and the water system were “among the best in the nation. Now, they are all among the worst.”

Born and raised in San Diego, the 44-year-old Allen looks every bit the Southern California surfer that he is. Short, spiky hair. Shirt unbuttoned two buttons. He offers fist bumps, occasionally addresses people as “dude,” and isn’t shy about speaking about himself in the third person.

After attending those Democratic fundraisers, he ran for office himself, winning election to the state Assembly in 2012 and easily being re-elected in 2014 and 2016. But it’s hard to fundamentally change California as a backbench Republican in a Democratic-dominated Legislature. So, inspired by Trump’s unlikely victory, he decided to run for governor and adopted the president’s blunt rhetorical style.

The California he sees is full of “exploding homelessness” and “rising violent crime.” “Gavin Newsom’s San Francisco” is a dystopia where the “streets stink” and “there are maps of human waste so you know which streets to walk on and which to avoid.”

“The sidewalks glitter, and it’s not diamonds,” Allen told The Chronicle in a Facebook Live conversation. It’s the glass from smashed-in car windows.”

California’s problems “emanate right here in San Francisco,” the home base of “Bay Area liberal elites” who have ruined the state, Allen said. Like Newsom.

“And there is one guy who is going to beat Gavin Newsom,” Allen said. “And that is Travis Allen.”

Allen says one big difference between him and Cox is that he voted for Trump in 2016, while Cox backed Libertarian Party nominee Gary Johnson. Cox says he wasn’t sure Trump was a real conservative, but now he is.

Allen misses few chances to knock Cox for his vote, and that’s helped him attract Trump supporters as volunteers. Whether they’ll stick with him now that the president has backed Cox is what could make or break his candidacy, because Allen has few resources beyond free labor. He had just $147,609 cash on hand at the end of April, barely one-tenth Cox’s total.

Like Trump, he attacks his opponents with gusto. He mocks Cox as “an angry guy” and a “beta male.” Referring to then-San Francisco Mayor Newsom’s 2005 affair with a staffer who was married to his campaign manager, Allen asked a debate audience, “If you can’t trust Gavin with your best friend’s wife, how can you trust him with the state?”

He touts his 100 percent rating from the anti-tax Howard Jarvis Taxpayers Association as strongly as he does his zero percent rating from Planned Parenthood. In Trump fashion, he seeks to connect to voters with a simply worded message: “Cut taxes, get tough on crime, fix our roads and expand our freeways with no new taxes, fix our broken education system, and complete the California state water project.”

He offers few policy details beyond his promises to “fix” and “get tough,” even on his campaign website. But as Trump did in 2016, Allen has a list of things he would do “on day one” after taking office, like overturning California’s sanctuary state laws and its 12-cent-a-gallon gasoline tax increase.

Doing any of that will be hard, because the Legislature is certain to still be in Democratic control. But Allen is unfazed. His plan will work, he says, because “Californians don’t want California to look like the streets of San Francisco.”

As for Trump’s endorsement of Cox, Allen stayed on message: “CALIFORNIANS DESERVE A GREAT GOVERNOR,” he tweeted Friday. “One who actually VOTED for President @realDonaldTrump — @JoinTravisAllen.”

John Cox

Cox, 62, grew up on the South Side of Chicago and was raised by a single mother, a schoolteacher he calls “my hero.”

She labored under principals who retained their jobs with the help of “corrupt local politicians,” Cox says. The experience formed his view of politics as a system soiled by money and corruption.

He worked his way through Illinois Institute of Technology, graduating in 2½ years at the age of 20. Afterward, he had a day job as a certified public accountant — by night, he went to law school at Chicago-Kent College of Law.

In 1981, he opened a law firm. Later, he branched off into the worlds of venture capital and real estate and amassed a fortune.

Slowly, he became interested in politics. He served on the steering committee of Jack Kemp’s failed 1988 GOP presidential campaign. Then he began a series of unsuccessful runs for office in Illinois — for Congress, the U.S. Senate and Cook County recorder of deeds. In 2007, he briefly ran for president.

Seven years ago, he moved to the wealthy community of Rancho Santa Fe north of San Diego, and brought his jaded view of politics with him.

In 2016, he spent more than $373,000 on an unsuccessful attempt to qualify a ballot measure to force politicians to wear the corporate logos of their top donors when they appear at official functions — similar to how NASCAR drivers sport their sponsors’ logos.

Cox said it was a way to show the “absurdity” of the influence that wealthy people have on the political system. Yet in 2018, Cox has spent more than $4.2 million of his own money on his campaign for governor. Last year, he spent $2 million on another unsuccessful ballot measure, one that would have had voters elect as many as 12,000 local representatives to advise the 120 members of the Legislature in Sacramento.

To Cox, a thread runs through all his efforts: “I’m a businessman. A problem-solver. I’m not like these politicians.”

Some opponents have said anyone who runs for office five times is, by definition, a politician. Cox makes the distinction that he doesn’t want “a career in politics. I love running my business. I’m interested in doing this because this state needs a business perspective. It needs someone who has had management experience. It is not being very well managed.”

On policies, Cox concedes, there’s not much difference between him and Allen. They both oppose the gas tax increase and sanctuary state laws. It’s more a question of style: Cox, with his shock of white hair and dark-rimmed glasses, says in his flat Midwestern accent that his surfer-dude Republican adversary is “immature.”

Over the past few weeks, some party leaders have tried to coalesce support around Cox — House Majority Leader Kevin McCarthy of Bakersfield, a popular figure in California GOP circles, was well ahead of Trump in endorsing him.

But when party delegates met at their convention this month in San Diego, it made no difference — both candidates fell short of the votes needed to win an endorsement.

It left California Republicans divided over which candidate to choose. Again.

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli