Former U.S. President and Republican frontrunner Donald Trump clinched a comfortable victory in New Hampshire primaries Tuesday, taking him a step closer to a November rematch with Democratic President Joe Biden.

Trump's only remaining rival, former U.N. Ambassador Nikki Haley, however, has vowed to soldier on despite a defeat.

"This race is far from over," she told supporters at a post-election party in Concord, challenging Trump to debate her. "I'm a fighter. And I'm scrappy. And now we're the last one standing next to Donald Trump."

At his own party in Nashua, Trump opened his speech by mocking Haley, calling her an "imposter" and saying, "She's doing, like, a speech like she won. She didn't win. She lost ... She had a very bad night." His remarks followed a series of angry posts on his Truth Social app, denouncing her as "DELUSIONAL."

With 57% of the expected vote tallied, according to Edison Research, Trump held a comfortable 54.4% to 43.6% lead.

Haley had hoped the Northeastern state's sizable cadre of independent voters would carry her to an upset win that might loosen Trump's iron grip on the Republican Party.

Instead, Trump became the first Republican to sweep competitive votes in both Iowa – where he won by a record-setting margin eight days ago – and New Hampshire since 1976, when the two states cemented their status as the first nominating contests.

While the final margin was still unclear, the result will likely bolster some Republicans' calls for Haley to drop out so the party can coalesce behind Trump. Her campaign vowed in a memo earlier on Tuesday to push forward until "Super Tuesday" on March 5, when Republicans in 15 states and one territory vote.

The next competitive contest is scheduled for Feb. 24 in South Carolina, where Haley was born and served two terms as governor. Despite her ties, however, Trump has racked up endorsements from most of the state's Republican figures, and opinion polls show him with a wide lead.

Tuesday's vote was the first one-on-one matchup between Trump and Haley, after Florida Governor Ron DeSantis, once seen as Trump's most formidable challenger, dropped out on Sunday and endorsed Trump. Though DeSantis had only marginal support in New Hampshire, his voters were far likelier to switch allegiance to Trump, rather than to Haley, according to polls.

Meanwhile, Edison projected Biden would win the New Hampshire Democratic primary, brushing aside his challenger, U.S. Representative Dean Phillips.

Despite Trump's win Tuesday, exit polls hinted at his potential vulnerabilities in a general election campaign. He faces 91 criminal charges for a range of offenses, including his efforts to overturn his 2020 defeat and his retention of classified documents after leaving the White House in 2021. He has denied any wrongdoing and claimed to be a victim of political persecution.

About 42% of voters who participated in the Republican primary said he would not be fit to serve if convicted in court, according to exit polling by Edison.

There were also warning signs for Biden, however. Three-quarters of Republican primary voters said the economy was either poor or not good, an area where Biden has struggled to highlight his administration's accomplishments.

Republicans made up a slightly smaller share of voters in the primary relative to the state's 2016 Republican contest in the state, the exit polls showed. Some 51% of voters considered themselves Republican, compared to 55% in the 2016 primary. Nearly, 6% said they considered themselves Democrats, compared to 3% in 2016. The share of independents was little changed at 43%.

Biden not on ballot

Biden declined to appear on the ballot in New Hampshire's Democratic primary, having supported an effort by his party to move their first primary election to the more diverse state of South Carolina.

New Hampshire supporters were still able to vote for Biden by writing his name on the ballot, offering a barometer of his political strength. With 29% of the estimated vote counted, according to Edison, Biden had 67.7%, far ahead of Phillips at 19.4%.

The Democratic president, whose advisers are anticipating a rematch with Trump, took aim at Republicans over their efforts to curb abortion rights in a Virginia speech Tuesday.

In a statement later, Biden said: "It is now clear that Donald Trump will be the Republican nominee. And my message to the country is the stakes could not be higher. Our democracy. Our personal freedoms – from the right to choose to the right to vote. Our economy – which has seen the strongest recovery in the world since COVID."

New Hampshire, while a mostly white state with a small population like Iowa, has a more moderate Republican electorate and a better record of predicting the eventual nominee.

Haley had stepped up her attacks on Trump as the election drew near, criticizing his affinity for strongmen such as North Korea's Kim Jong Un.

Haley, 52, has also gone after Trump's age – he is 77 – and mental acuity, attacks she has also regularly leveled at Biden, who is 81.

In her speech on Tuesday, Haley warned that Trump would lose to Biden again if nominated.

"The worst-kept secret in politics is how badly the Democrats want to run against Donald Trump," she said. "They know Trump is the only Republican in the country who Joe Biden can defeat."