Republican Steve Hilton, the former UK political operative turned Fox News personality, has advanced to the November general election in the race to become California’s next governor, facing off against Democrat Xavier Becerra, a former congressman, state attorney general and US health secretary.

Hilton’s success, a remarkable achievement for a recent immigrant, came after he was endorsed by Donald Trump.

The Associated Press projected that Hilton would secure one of the top two spots in the nonpartisan primary election, which was held on 2 June.

Hilton was in second place behind Becerra, who unexpectedly but steadily consolidated support among Democratic voters.

When the first votes were counted last week, Hilton initially led the field, prompting Trump to prematurely declare him the winner. By the next day, as Becerra won more of the votes counted late, Trump, without evidence, accused the state of election-rigging.

But as California counted millions more ballots sent by mail, Hilton was overtaken by Becerra on 5 June. Hilton still finished ahead of Tom Steyer, the billionaire hedge fund investor running as a progressive.

Steyer released a concessionary statement on Tuesday evening, thanking his supporters and vowing to remain committed to the fight.

For his part, Hilton acted as if he had won the primary from the morning after the election, when he stopped just short of declaring victory, but said: “Change is coming, and the campaign for change starts today.”

The rise of the newly minted American, who left his native Britain for the San Francisco Bay Area in 2012 and became a US citizen in 2021, as a serious contender to be California’s governor has surprised former colleagues in the UK, where he was a prominent adviser to David Cameron, the Conservative prime minister at the time.

Hilton, who was known as the “pint-sized Rasputin” of Conservative politics, was known for inventing catchy slogans that caused some to cringe. Credited with coming up with the “hug a hoodie” campaign for Cameron’s government, Hilton is now claiming that a vote for him will make California “Califordable”.

As Cameron’s director of strategy, Hilton was known in political circles in London for his unorthodox working style. He would reportedly walk around the prime minister’s offices in socks, ordering civil servants to enact off-the-wall schemes that led to him being parodied in Armando Iannucci’s political satire The Thick of It, which set the template for the US TV series Veep.

Hilton still faces an uphill struggle to win in November in a heavily Democratic state. Running with Trump’s endorsement in a state where the president is deeply unpopular makes the path forward even more fraught.

In each of the last three California governor’s races, the Democratic candidate has taken about 60% of the vote. Democrats control nearly all levels of government in the state and hold a nearly two-to-one voter registration advantage.

Hilton’s attempt to cast himself as living what he calls “the California dream” can be seen in the images on his campaign website – which show him on a beach; at a Trump rally in Coachella, where the current president praised him; and holding an In-N-Out burger. Another effort to embrace the state’s culture fell flat however, when Hilton was widely mocked for referring to a hard-shell tortilla concoction he held in a social media video as a “street taco”, a style of taco traditionally made with two soft corn tortillas.

In a video posted on Tuesday evening, Hilton portrayed himself as an immigrant with working-class parents who moved to California because it was “the ultimate expression of America, the home of freedom”. Hilton vows to “save California” and says: “I’m not a politician. I’m an outsider, running for governor to shake up a broken system.”

Hilton has called himself “a pragmatist, not an ideologue”, and has said his experience in a coalition government during Cameron’s premiership is proof that he can work well with people whose politics do not align with his. He has said the fact that he gets along with Trump and his cabinet is a potential asset, and can attract federal dollars and other forms of cooperation from Washington that will lower the temperature after more than a year of feuding and name-calling between Trump and Gavin Newsom, California’s current governor.

“My job,” Hilton told the Guardian last month, “will be to deliver pretty pragmatic things, all focused on making your life easier and better.”

Andrew Gumbel and Helena Horton contributed reporting