Ron DeSantis has suspended his campaign for president and endorsed Donald Trump as the Republican nominee for the White House in 2024, in a significant blow to Nikki Haley with just two days to go until the New Hampshire primary.

DeSantis announced his decision in a video posted to social media on Sunday afternoon, saying he and his wife, Casey, had “prayed and deliberated on the way forward” after his second-place finish in last week’s Iowa caucuses.

“I can’t ask our supporters to volunteer their time and donate their resources if we don’t have a clear path to victory,” DeSantis said as he confirmed he was suspending his campaign.

The Florida governor said it was “clear . . . that a majority of Republican primary voters want to give Donald Trump another chance,” adding: “They watched his presidency get stymied by relentless resistance and they see Democrats using lawfare to this day to attack him.”

During the campaign Trump attacked DeSantis in brutally personal terms, mocking the governor for apparently wearing shoe lifts, calling him “Ron DeSanctimonious” and saying he needed a “personality transplant.”

On Sunday, DeSantis said he had “disagreements” with Trump but the former president was “superior” to Democratic incumbent President Joe Biden.

“[Trump] has my endorsement because we can’t go back to the old Republican guard of yesteryear, a repackaged form of warmed-over corporatism that Nikki Haley represents,” DeSantis added.

Haley responded to DeSantis’s announcement at a campaign stop in New Hampshire on Sunday afternoon, saying: “He ran a great race. He has been a good governor, and we wish him well. Having said that, it’s now one fella and one lady left . . . may the best woman win.”

The Trump campaign said it was “honoured” by the endorsement, adding that Haley was the candidate of globalists and Democrats, in a statement on X.

DeSantis’s departure from the race comes just two days before the New Hampshire primary, which will now be a clear two-person race between Trump and Haley, the former South Carolina governor who later served as Trump’s ambassador to the UN.

Haley finished in a disappointing third place in last week’s Iowa caucuses, narrowly edged out by DeSantis. But she is betting that a coalition of more moderate Republicans looking for an alternative to Trump, as well as independent voters who are eligible to vote in the New Hampshire primary, will help her usurp her former boss there.

Recent opinion polls, however, illustrate the steep uphill climb Haley is facing heading into Tuesday. The latest FiveThirtyEight average of polls in New Hampshire shows Trump commands the support of just under 49 per cent of likely primary voters, followed by Haley on around 34 per cent. DeSantis trailed in a distant third place, on about five per cent, prior to dropping out.

A year ago, DeSantis, 45, appeared to be the Republican best positioned to take on Trump. The former congressman won re-election as governor of Florida in the 2022 midterms by nearly 20 points, with voters there rewarding him for his handling of the Covid-19 pandemic.

He became known as a warrior against “woke” ideology, launching a hard-charging campaign over progressive views on gender identity and sexual orientation, tossing aside companies like Disney, schools and the media that opposed him. A pro-DeSantis “super Pac”, Never Back Down, amassed more than $130mn for his White House run.

But after state and federal prosecutors launched four criminal cases against Trump, including over charges alleging that he conspired to overturn the 2020 election, Republicans increasingly rallied around the former president. 

Nevada businessman Joe DeSimone, a DeSantis donor, told the FT that DeSantis was a “victim of circumstance,” who could not overcome Republicans’ urge to defend Trump.

“All the legal action that was addressed at Trump seemed to really fire up his base and get them motivated to come out and vote and contribute,” said DeSimone, who will now support the former president.

But DeSantis also made several public mis-steps and his campaign was plagued by overspending and staff infighting. He appeared awkward at times on the campaign trail, and ultimately only appealed to a narrow band of orthodox conservatives.

His super Pac took much of the campaign’s traditional role in fundraising, organising travel, knocking on doors and airing ads. But as DeSantis started to fall in the polls, and Haley started to rise, the relationship between the two organisations, which are legally barred from coordinating, became increasingly strained. 

In the autumn, DeSantis’s biggest donor, Robert Bigelow, a Nevada real estate investor who gave Never Back Down over $20mn, told the FT he was considering backing Trump instead after DeSantis did not call him following his public criticism of the governor’s decision to sign a six-week abortion ban bill. Never Back Down ultimately saw the departure of two chief executives, its board chair, and other staff.

Two DeSantis donors had recently told the FT that their candidate had raised enough money to campaign at least until South Carolina held its vote on February 24. 

But there were signs of his campaign’s imminent collapse. Since the Iowa caucuses on January 15, pro-DeSantis groups have spent less than $100,000 on advertisements, according to AdImpact data. Pro-Haley groups, meanwhile, have spent more than $7.8mn.

David Paleologos, the director of the Suffolk University political research center, said that DeSantis’ decision will help Trump more than Haley in New Hampshire.

“In our last track, the small subset of DeSantis voters broke to Trump 57 per cent to 33 per cent,” Paleologos told the FT.