DeSantis exits 2024 race right after aide says he won't; Trump responds after Haley questions mental fitness

Florida Gov. Ron DeSantis ended his presidential campaign on Sunday amid dour poll numbers in New Hampshire and South Carolina, marking a major shift in the primary field and the downfall of a politician once seen as former President Donald Trump's chief rival.

Meanwhile, Trump and former South Carolina Gov. Nikki Haley are growing increasingly combative on the trail ahead of New Hampshire's primary on Tuesday, where polls show Haley has her best chance at beating Trump.

As Trump defends his attacks on Haley based on her name, Haley has been going after Trump over his age and, she argues, his decline in mental stamina.

Here's where the trail stands with less than two days before New Hampshire votes.

DeSantis leaves the race

DeSantis announced in a video shared to social media that he was leaving the race for president, marking the exit of another major candidate shortly before Tuesday's New Hampshire primary. The race essentially consists of Trump and Haley.

DeSantis in the video endorsed Trump while noting disagreements with the former president over issues like his handling of the COVID-19 pandemic.

The governor's departure will see his support in New Hampshire divvied up by the remaining field. Trump is looking to build an early winning streak, after last week's Iowa caucuses, while Haley is looking at her best chance to best Trump, per state polling, which shows her a relatively close No. 2.

Trump won more than 50% of the vote in Iowa, and DeSantis -- who had previously projected he would win there -- got a distant second place, with 21%. That was a major setback for a rising Republican star who had cruised to reelection in 2022 in a famous swing state where he built a track record as a successful, often hard-line conservative.

DeSantis' decision to leave the race had been the subject of mounting speculation this weekend after he canceled high-profile scheduled appearances on Sunday on NBC and CNN and on WMUR, a New Hampshire TV station.

He had also been set to spend most of this weekend campaigning in South Carolina in events hosted by his allied super PAC, Never Back Down, but then planned to return to New Hampshire on Sunday for an event in Manchester.

DeSantis' campaign even insisted less than a day before that he would remain in the race.

"The media hits were canceled due to a scheduling issue and will be rescheduled. The governor will be traveling Sunday morning with the campaign and has public events scheduled Sunday evening through Tuesday in NH," campaign spokesperson Bryan Griffin posted on X, the platform formerly known as Twitter.

Trump and Haley go at it with different attacks

Trump has, more and more, been mispronouncing or misstating Haley's given first name -- Nimarata -- in his social media posts and in public, echoing his repeated emphasis on Barack Obama's middle name, Hussein.

Trump has also elevated the racist conspiracy theory that Haley is not eligible to be president of the United States because her Indian immigrant parents weren't yet citizens when she was born in South Carolina. He infamously floated a similar baseless claim about Obama.

Asked about him mocking Haley's name, Trump told Fox News' Bret Baier on Sunday that he had done something similar to former primary opponent Asa Hutchinson.

"It's a little bit of a take-off on her name and her name, wherever she may come from," he said.

"I have fun with it. And sometimes to tell you the truth, it's a very effective tool," he added.

Haley brushed off Trump's new slams, telling CNN on Thursday: "I know President Trump well. That's what he does when he feels threatened. That's what he does when he feels insecure."

Trump dismissed that on Sunday. "I'm not concerned with her," he told Baier.

Haley has also returned fire of her own, casting Trump, 77, as too old to return to the White House and questioning his mental acuity after he repeatedly confused her with former House Speaker Nancy Pelosi, D-Calif., in recent comments about the Jan. 6 attack on the U.S. Capitol.

"The concern I have is -- I'm not saying anything derogatory -- but when you're dealing with the pressures of a presidency, we can't have someone else that we question whether they're mentally fit to do it," Haley said Saturday in New Hampshire. She has repeatedly indicated both Trump and President Joe Biden, who is 81, are too old for office.

She reiterated her criticism of Trump on Sunday on CBS' "Face the Nation."

"You don't be surprised if you have someone that's 80 in office, their mental stability is going to continue to decline. That's just human nature. We know that," she said. "What I'm saying is, first of all, you're talking about somebody who's only going to be an office for four years. Secondly, you're talking about someone who continues to I mean, look, I don't know if he was confused. I don't know what happened. But it should be enough to send us a warning sign."

Biden's campaign weighed in as well, with a sarcastic post on X that read "I don't agree with Nikki Haley on everything, but we agree on this much: She is not Nancy Pelosi."

On Saturday night, Trump said his mind is "stronger" than it was 25 years ago and jabbed at Biden, who has made a number of verbal gaffes and slip-ups himself.

Sununu boasts of Haley's chances in NH but dodges on path forward

New Hampshire Gov. Chris Sununu, one of Haley's top surrogates, boasted of her chances in his state -- but he sounded less bullish when discussing her path forward beyond that race.

According to 538, Haley is behind Trump in New Hampshire by about 15 points, though she is banking on the state's independent voters rallying to her over him.

"I'm looking at the next 72 hours," Sununu said on NBC's "Meet the Press" on Sunday. "We're going like gangbusters. She's crisscrossing the state. She's hitting every voter. She's going everywhere."

Still, when pressed on whether Haley would remain in the primary contest if she loses next month in her home state of South Carolina -- where 538's polling average shows Trump with a roughly 30-point advantage -- Sununu demurred, saying that Haley could "build on momentum" from a strong finish in New Hampshire.

"I think after every state, you look at your campaign, obviously, but that's a month away. I mean, it's really a month away," he said.

ABC News' Gabriella Abdul-Hakim, Libby Cathey, Hannah Demissie, Fritz Farrow, Lalee Ibssa and Soo Rin Kim contributed to this report.