In a packed opera house on Tuesday night in Derry, N.H., Hannah Kesselring had a pressing question for Nikki Haley, one that many voters in the room appear to have been considering as Ms. Haley has climbed in the 2024 Republican presidential contest.
A punchy 9-year-old decked in a red and navy blue Haley cap, Hannah had gone viral when she spoke up at another Haley town hall before Thanksgiving. She had since had the chance to see Ron DeSantis and Vivek Ramaswamy stump in her state, she told Ms. Haley. Now, she wanted to know three reasons Ms. Haley “believed she should be elected president over them.”
Ms. Haley, a former governor of South Carolina and a former United Nations ambassador, didn’t skip a beat. She ticked off her executive experience, her foreign policy credentials and her concern for the state of the country and the world.
“I am a mom,” she said to several nods in the room. “And the truth is, I don’t want my kids growing up like this.”
It was the kind of exchange that Ms. Haley has used to steadily build momentum — and it seems to be paying off.
In diners, gyms and event halls across New Hampshire and South Carolina, the state she led for six years, voters have recently shown increased interest in Ms. Haley’s campaign, with a palpable shift in energy. For some, the hope that she might be able to consolidate the wing of her party craving an alternative to former President Donald J. Trump has become less far-fetched.
At her town hall in Derry, where almost half the people in the audience raised their hands when she asked if this was their first time watching her speak, Ms. Haley drew louder cheers beyond her usual applause lines. One day earlier, in Bluffton, S.C., she had addressed a buoyant audience of roughly 2,500 people — the largest yet in her home state — walking onstage to “Eye of the Tiger,” her standard opener, and chants of “Haley, Haley, Haley.”
“We have one more fella we have to catch up to,” she said at that event, referring to Mr. Trump.
In South Carolina, where her homecoming had the feel of a rally, Ms. Haley’s message appeared to resonate. Her campaign officials said they had to move the event to a larger location last week after so many people signed up to attend.
But she still has a lot of convincing to do. Ms. Haley remains far behind the former president she served under, who continues to dominate in national polls, as well as in surveys in every early-voting state.
In Iowa, her toughest challenger for second place is Mr. DeSantis, the Florida governor, who has made the state pivotal to his prospects. In New Hampshire, where she comfortably holds the second slot, it is former Gov. Chris Christie of New Jersey who has been gaining ground in his do-or-die state.
At Ms. Haley’s town hall in Derry, several voters warmed up to her but were not yet necessarily convinced. Teri and Donald Synborski were still weighing Ms. Haley, Mr. DeSantis and Mr. Christie — anyone but Mr. Trump, they said. Mr. Synborski, 67, a corporate finance managing director, had caught wind of Ms. Haley’s momentum when first saw her speak at a crowded diner in Londonderry not too long ago. The room was so packed, he recalled, that reporters were pushed up against him.
Still, he said he would probably like to see Mr. DeSantis one more time before making up his mind. “He would really have to do something earth-shattering for me to be swayed to vote for him versus Nikki,” he added. “I’m leaning heavily in her direction, but I still call myself undecided.”
That alone is progress for Ms. Haley. There was a time when political strategists and observers likened her path in New Hampshire to the steep and narrow road leading to the tallest peak in New England, a feat captured on a popular state bumper sticker: “This car climbed Mt. Washington.”
But her rise there and beyond can be attributed to a grueling pace in the early-voting states, a series of standout debate performances and new interest among powerful players in the Republican Party’s donor class after two contenders — former Vice President Mike Pence and Senator Tim Scott, a fellow South Carolinian — folded their bids this fall.
The political network founded by the billionaire industrialist brothers Charles and David Koch endorsed her campaign on Tuesday, giving her another financial boost and access to a direct-mail operation, field workers to knock on doors and people to call up prospective voters. Kenneth G. Langone, the billionaire Home Depot co-founder, who has donated to Ms. Haley’s campaign, is considering giving more and is expected to meet with her next week in New York.
As she has risen, her rivals have taken notice. In recent national television interviews, Mr. Christie has kept up his criticism of Ms. Haley over what he describes as her unwillingness to take on Mr. Trump — “Either run against him or don’t run against him” — and her comments at an Iowa event before a conservative Christian audience, in which she said she would have signed a six-week ban on abortion when she was governor.
“I want to be clear that there is no consensus around a six-week national abortion ban, and I wouldn’t sign it if I were president even,” Mr. Christie told CNBC’s “Squawk Box,” saying that would be putting such a decision “into the hands of politicians over people.”
In an interview, Austin McCubbin, the state director for the Trump campaign in South Carolina, described Ms. Haley as a “paper tiger,” arguing that she had “absolutely no political operation in South Carolina,” nor representatives actively attending and engaged in local G.O.P. meetings. Trump campaign officials say that Mr. Trump has 83 endorsements from state lawmakers — more than all other Republicans combined.
Responding to a request for comment on the arguments from the Trump campaign, Olivia Perez-Cubas, a spokeswoman for Ms. Haley, said, “Americans are ready for a new-generation, conservative leader who will leave the drama and chaos behind.”
Pacing before New Hampshire voters at the Derry Opera House, Ms. Haley seemed to ignore her critics and once more made the case for herself, saying it was time for Republicans to “acknowledge some hard truths” — specifically, her party has lost the popular vote for president in seven of the last eight elections.
“This isn’t just about the presidency,” she said, contending that her candidacy would be a windfall down the ballot. “This is about governorships up and down. This is about House seats. This is about Senate seats. This is about truly righting the ship to get us back to where we need to be.”