SEABROOK, N.H. — Since the Iowa caucuses, Nikki Haley had tried to frame the Republican presidential race as one-on-one combat between her and Donald Trump.

On Sunday, Florida Gov. Ron DeSantis made it official for Haley, who appeared noticeably energized as she delivered the news of his exit at a campaign stop — even though the question of just how much it will help her looms over the shrinking primary campaign.

“Boy, are things changing fast,” Haley, the former U.N. ambassador, said at Brown’s Lobster Pound.

“We just heard that Ron DeSantis has dropped out of the race,” she continued as huge applause erupted from restaurant-goers and volunteers. “I want to say to Ron he 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 left.”

She added later, “May the best woman win.”

Inside the Haley campaign, there’s a sense of energy over the news of DeSantis’ dropping out, though officials there don’t think it will make much of a difference when it comes to the numbers, pointing to public surveys showing DeSantis in the single digits in both South Carolina and New Hampshire. In that sense, they believe that’s why it was a two-person race before DeSantis dropped out.

“This is a boost,” said a person familiar with the campaign’s thinking, arguing that it proves Haley is an outsider.

Regardless of DeSantis’ endorsement of Trump, the Haley campaign believes his voters will be divided up between her and the former president. What’s more, they see it as a clarion call to voters who are unenthusiastic about a Trump-vs.-Joe Biden rematch that it’s time to get behind Haley, the former governor of South Carolina.

Rick Wiley, a Haley adviser, tweeted, “The utter humiliation,” as news of DeSantis’ stepping aside broke.

Other advisers never entertained the possibility that DeSantis would endorse Haley. Unlike the sting of the endorsement of Trump by Sen. Tim Scott of South Carolina, this moment carried far less weight and sense of betrayal.

New Hampshire has so far been the early state that is most favorable to Haley’s candidacy, but Trump still holds double-digit leads in most recent surveys of the GOP primary. While she leads among independent voters who are allowed to participate in the state’s open primary, the polls show Trump with a wider lead among registered Republicans, giving him the overall advantage.

DeSantis, meanwhile, has hardly registered in the most recent New Hampshire polls, consistently showing up in the mid-single digits. The sample sizes were small, but DeSantis supporters were more likely to pick Trump than Haley as their second choices in both the most recent University of New Hampshire/CNN poll and Suffolk University’s tracking poll with The Boston Globe and NBC Boston.

Still, Haley supporters see DeSantis’ leaving the race as a sign of her strengthening candidacy.

South Carolina state Rep. Chris Wooten, a Haley supporter, said he believes DeSantis “realized that he couldn’t beat her.”

“It is such a boost for Nikki,” he added. “She predicted this two weeks ago, and she has an amazing opportunity now with all the distractors out of the race.”

South Carolina state Sen. Tom Davis, another Haley backer, said the new one-on-one contest will better allow Haley to contrast herself with Trump, adding that South Carolina’s primary will now serve as a “referendum” on what the Republican Party will be going forward.

“Does the party want to look forward and address issues that desperately need solving — decreasing the debt and deficits, making Social Security solvent, fixing a porous southern border? Those are the things Nikki Haley focuses on,” Davis said. “Or does it want to be a party that looks backward and settles scores for perceived past grievances, one that seeks ‘retribution’? Those are the things Donald Trump emphasizes.”

But even as the development gave Haley a bounce in her step heading into Tuesday’s primary, some New Hampshire Republicans and other political observers offered a bleak forecast.

“I really think Haley’s only chance is if the undeclared independents show up in droves on Tuesday. If they don’t, she’s going to get killed,” said Sean Van Anglen, a New Hampshire Republican who opposes Trump and said he will most likely vote for Haley. “That’s really her only hope. If she loses New Hampshire, it’s done. Unfortunately, it seems like she’s going to lose.”

A Trump-aligned operative had a harsh assessment of what DeSantis’ exit would — or rather, wouldn’t — mean for Haley.

“She’s going to lose,” this person said. “By a lot.”

Terry Sullivan, Sen. Marco Rubio’s presidential campaign manager in 2016, said DeSantis’ departure makes little difference in how the primary campaign will play out.

“Republican primary is over,” he said. “It has been for a while. Ron DeSantis now just figured it out. I assume it will be only a matter of days before Nikki Haley does, too. She won’t even make it to South Carolina.”

This article was originally published on NBCNews.com