Florida Governor Ron DeSantis, who was once the leading Republican rival to Donald Trump, ended his election campaign on Sunday and threw his support behind the former president.
DeSantis's withdrawal, after months of weakening support, leaves only low-polling Nikki Haley standing between Trump and the nomination as the Republican Party's candidate for the US presidential election in November.
In a video message, DeSantis said that following his second place finish last week in the Iowa caucuses he could not "ask our supporters to volunteer their time and donate their resources if we don't have a clear path to victory. Accordingly, I am today suspending my campaign."
The decision came less than two days before the New Hampshire primary, where polls showed him far behind front-runner Trump and former UN ambassador Haley.
"It's clear to me that a majority of Republican primary voters want to give Donald Trump another chance," DeSantis said, noting he has had differences with the former president, notably over the coronavirus pandemic.
"He has my endorsement because we can't go back to the old Republican guard of yesteryear or (a) repackaged form of warmed-over corporatism that Nikki Haley represents."
Trump stormed to victory in Iowa last Tuesday, with 51 percent of Republican voters choosing the twice-impeached former president over DeSantis, who gained only 21 percent, and Haley at 19 percent.
No candidate has ever lost the race after claiming the first two states, and Trump would almost certainly declare the Republican nomination over with a win in New Hampshire.
Many Republicans had pinned their hopes on DeSantis, who at just 45 was embraced by some as a rising star of right.
But his candidacy, announced at the end of May, struggled to establish itself as a threat to Trump, 77.
DeSantis, a former naval officer, was elected in 2018 as governor in Florida after receiving the valuable endorsement of Trump.
Since then, he often distanced himself from Trump and gained notoriety for a series of hard-right stances on education, immigration and LGBTQ issues.
DeSantis appeared almost daily in the national media to lock horns in the cultural wars against "woke" politicians, businesses and professors he accuses of forcing their progressive ideology on Americans.
His most headline-grabbing initiatives have included allowing Floridians to carry concealed guns without a permit and imposing one of the country's most restrictive abortion laws.
Ahead of the New Hampshire vote on Tuesday, Haley had largely refrained from hitting out at Trump, but she has begun questioning his mental acuity, making comparisons between him and the 81-year-old incumbent Democrat Joe Biden.
At an event in Seabrook, New Hampshire, she said DeSantis "ran a great race, he's been a good governor, and we wish him well."
"Having said that, it's now one fella and one lady," she continued.
"This comes down to 'what do you want.' Do you want more of the same or do you want something new?"
