MANCHESTER, N.H. — Former President Donald Trump is aiming for a commanding victory Tuesday in New Hampshire, sure of a sweep of the first two Republican primary races to make a November rematch with President Joe Biden more likely than ever.

Nikki Haley, Trump's last remaining major GOP rival, insisted that she would not concede an early knockout as she visited polling sites, even as Trump's allies ramped up pressure on her to leave the race if she loses by a large margin. The former U.N. ambassador has focused considerable resources on New Hampshire, hoping to capitalize on the state’s independent streak as she looks for an upset or at least a tight loss that could dent Trump’s continued domination of Republican politics.

“I’m running against Donald Trump, and I’m not going to talk about an obituary,” Haley told reporters.

There was a Democratic New Hampshire primary, too, but it was unsanctioned and provided no delegates to the winner. President Joe Biden wasn't on that ballot, opting to wait for upcoming South Carolina.

If Trump wins Tuesday, he would be the first Republican presidential candidate to win open races in Iowa and New Hampshire since both states began leading the election calendar in 1976 — a sign of his continued grip on the party’s most loyal voters and a suggestion that he would extend his winning streak no matter how long Haley remained in the race.

Trump won New Hampshire’s Republican primary big during his first run for president in 2016, though some of his allies lost key races during the midterms two years ago. Haley has to contend with an opponent who has a deep bond with the GOP base and has concentrated on winning New Hampshire decisively enough that it would end the competitive phase of the Republican nomination battle.

Were Haley to drop out after Tuesday, that would effectively decide the GOP primary on its second stop, well before the vast majority of Republican voters across the country have been able to vote. Trump’s circle intensified its calls for Haley to step aside if he wins New Hampshire easily after his 30-point romp in the Iowa caucuses. Haley finished third in Iowa, behind Florida Gov. Ron DeSantis, who ended his campaign on Sunday.

Her campaign manager circulated a memo to Haley donors, supporters and media arguing that it was too early to dismiss her path forward —- while also tamping down expectations for New Hampshire.

“The political class and the media want to give Donald Trump a coronation,” Betsy Ankney wrote in the memo, first reported by The New York Times. “They say the race is over. They want to throw up their hands, after only 110,000 people have voted in a caucus in Iowa and say, well, I guess it’s Trump. That isn’t how this works.”

About 40% of New Hampshire’s registered voters are not affiliated by party. Republicans allow those voters to cast GOP primary ballots, opening Haley's potential coalition to more right-leaning voters who dislike Trump and even Democratic-leaning voters who want to oppose Trump or vent frustrations over Biden, who declined to campaign in his party's unsanctioned primary here after championing a new calendar that puts South Carolina first.

Laurie Dufour was among the independents who opted for Haley on Tuesday. She said she votes most often for Democrats and would vote for Biden “in a heartbeat” over Trump in a general election, though she said she wished Biden would consider stepping aside due to his age.

“I did not want Trump and she just sounded very knowledgeable,” the 66-year-old said.

Haley has been campaigning with New Hampshire’s popular Republican governor, Chris Sununu, a Trump critic. But she noted that many Republican power brokers have lined up behind Trump, effectively contradicting the former president's anti-establishment posturing.

“It's the political elite that are uniting around President Trump,” Haley insisted. “The political class has gotten us into this mess. We need a normal, real person to get us out of it.”

Haley could get a lift from some supporters of former New Jersey Gov. Chris Christie, who campaigned decrying Trump but ended his bid shortly before Iowa's caucus last week. Trump, meanwhile, may be able to consolidate support from conservative voters who were supporting DeSantis.

In the first results released early Tuesday, all six registered voters of tiny Dixville Notch cast their ballots for Haley over Trump. The resort town is the only one in New Hampshire this year that opted to vote at midnight.

Trump, who appeared Monday night at a pre-primary rally in Laconia with one of his former primary rivals, South Carolina Sen. Tim Scott, was already looking ahead. Asked during a Monday interview with Newsmax about Haley possibly abandoning her campaign after New Hampshire, the former president said he’d never call on her to do that but added, “Maybe she’ll be dropping out Tuesday.”

Scot Stebbins Sr., who attended Trump's rally in a Make America Great Again baseball cap, called him “the greatest president we’ve had since Abraham Lincoln,” adding that Trump “has done nothing but good for our nation.”

Stebbins said he thought the four criminal cases and 91 felony counts Trump is facing constituted “a witch hunt” and said Trump would “get rid of all the corrupt politicians who have been in there too long that are getting paid off.”

“He can’t be bought,” Stebbins said. “He’s a true American. He always has been.”

Democrats were also holding a primary Tuesday, but it was unlike any in recent memory.

Biden championed new Democratic National Committee rules that have the party's 2024 primary process beginning on Feb. 3 in South Carolina, rather than in Iowa or New Hampshire. He argued that Black voters, the party’s most reliable constituency and a critical part of his win in South Carolina that revived his 2020 primary campaign after three opening loses, should have a larger and earlier role in determining its nominee.

New Hampshire’s Democrats, citing state laws dictating that their state hold the nation’s first primary after Iowa’s caucuses, defied the revamped order and pushed ahead with their primary as scheduled.

Biden didn’t campaign here and his name won’t be on the ballot, meaning the state’s Democrats can vote for the president’s two little-known major primary challengers, Minnesota Rep. Dean Phillips and self-help author Marianne Williamson. Still, many of New Hampshire’s top Democrats backed a write-in campaign that they expect Biden to handily win.

Instead of focusing on New Hampshire, Biden was joining Vice President Kamala Harris in northern Virginia for a rally in defense of abortion rights, which Democrats see as a winning issue for them across the country in November.

There's a growing sense of inevitability around November being a reprisal of Biden versus Trump. Both men have been criticized by their opponents over age — Biden is 81, Trump 77 — and each has painted the other as unfit for another White House term.

Public opinion polls suggest most Americans oppose a rematch. An AP-NORC Center for Public Affairs Research poll in December found that 56% of U.S. adults would be very or somewhat dissatisfied with Biden as the Democratic nominee — and 58% felt the same about Trump as the GOP pick.

Though Trump has twice won New Hampshire's Republican primary but lost the state in both of his general election campaigns. Biden finished a distant fifth in Democrats' 2020 primary before going on to win the nomination. In the November 2020 election, Biden won 52.7% of the vote to Trump's 45.4%.