Steve Hilton, the former senior adviser to British Prime Minister David Cameron, has lost his bid for California governor to Democrat Xavier Becerra.
Hilton, who was endorsed by President Donald Trump, faced an uphill battle as a Republican in the widely liberal state. His loss was projected within minutes of polls closing in California.
Polls had suggested he had a slim chance at victory, especially on an election night where Democrats saw historic wins. He had campaigned to "save" the state from what he described as overbearing bureaucracy and economic decline.
Becerra will be the state's first Latino governor in more than 150 years. He succeeds term-limited Gavin Newsom.
Becerra represented Los Angeles in Congress for 24 years and served as the state's top prosecutor before he became the Health and Human Services secretary in the Biden administration.
In contrast, Hilton - an architect of the UK Conservative Party's "Big Society" agenda under Cameron - presented himself as a political outsider in the governor's race.
His campaign pushed to restore affordability and opportunity in what he described as "the most incredible place in the world".
Both he and Becerra both focused their campaigns on the Golden State's high cost of living, housing affordability, energy policy and relations with the federal government.
"We fought and we won," Becerra said in a victory speech on Tuesday night in Sacramento, the state's capital. He noted that the last few years have been tough for the state under Trump's leadership but "we hung in there, fought back. It felt like mission: impossible, we knew it was mission: necessary".
He told supporters that, "you have now entered the Becerra era".
Hilton, also speaking at an event with supporters, acknowledged his loss and the so-called Democrat wave washing over much of the country, which allowed Democrats full control of the US Congress.
"Maybe this isn't the best year to be running for office as a Republican when you see what's going on around the country, but I tell you what, this is the best place to be running for office as a Republican because there is nowhere better than California," he said.
He called California "the greatest place in the greatest nation on earth" and said it was that was an honour and a joy to have travelled the state during his campaign.
He added: "The change we hoped for may be delayed but the change is coming".
The state governor's race kicked off with an array of contenders but came into focus when congressman Eric Swalwell, who appeared to be an early leader in the contest, dropped out of the race over sexual assault allegations, which he has denied.
Becerra and Hilton ultimately emerged as the frontrunners in the June primary, edging out progressive billionaire Tom Steyer.
