Former President Trump on Tuesday made modern GOP primary history with back-to-back wins in New Hampshire and Iowa.

The big picture: The first-in-nation primary was former UN ambassador Nikki Haley's best chance to prove she could run a competitive head-to-head race with Trump.

• On the Democratic side, President Biden won via a write-in campaign after not appearing on the ballot, AP projected.

Zoom in: Axios had two reporters on the ground in New Hampshire — Sophia Cai and Alex Thompson — and others filing dispatches from across the U.S.

Editor's note: This story was formerly a live blog and has been updated with developments and background throughout.

Why Biden won't be on the New Hampshire primary ballot

The DNC's convoluted clash with New Hampshire legislators left Biden in a position to clinch the state's nomination through only write-in votes, Axios' Shauneen Miranda reports.

• Democrats in early 2023 approved the president's proposed primary calendar, which was designed to allow states with racially diverse populations — like South Carolina — a bigger say in these early races.

New Hampshire legislators refused to surrender their coveted spot, violating the rules.

• Biden then chose to not have his name on the ballot in the Granite State.
• Go deeper on the grassroots campaign.

In Londonderry, voters line up all day

In Londonderry, N.H. — a GOP stronghold — turnout was on track to match or surpass 2016, Axios' Sophia Cai reports.

• Voters lined up outside Londonderry High School all day to cast their ballots.

By the numbers: As of mid-afternoon, 5,172 voters — 31% of all those registered — had cast ballots. That included more than 4,000 GOP ballots and around 1,150 for Democrats.

Trump's surprise N.H. fan club: Democrats

Many Democrats are rooting for a big Trump win Tuesday, which could effectively end the GOP presidential primary, Axios' Alex Thompson and Erin Doherty report.

• Why it matters: Biden's team believes that Trump becoming the presumptive Republican nominee for president would give a much-needed jolt of energy to voters and grassroots donors who don't want to see Trump back in the White House.

But some top Democrats worry that Biden's team is too optimistic.

• Many still recall Jim Messina — Barack Obama's 2012 campaign manager — hoping in early 2016 that Hillary Clinton would get to run against Trump.
• "I wake up every morning," Messina said then, "and drop to my knees and pray, 'Please, God, give me Donald Trump.'" Oops!
• Go deeper.

Flashback: How N.H. Republican winners fare

The Republican primary winner in New Hampshire has typically had a good shot at becoming the nominee, even after losing the Iowa caucuses, Axios' April Rubin reports.

• Future presidents including Ronald Reagan (1980), George H.W. Bush (1988) and Trump (2016) changed their campaign strategies after losing Iowa.

Haley is vying for a win in the Granite State, and has said that its voters will "correct" Iowa's results.

• But Trump's "anomaly" status as a candidate is expected to defy New Hampshire's tendency to course correct, said Ron Bonjean, a longtime Republican strategist.

Go deeper: 5 times New Hampshire brought hallelujah wins for Iowa losers

Why New Hampshire is Haley's best chance to beat Trump

Independent voters make up about 40% of New Hampshire's electorate, and Haley has aimed to appeal to a more moderate voter base, Axios' April Rubin writes.

• The state's Republicans are also less conservative and less evangelical than Iowa Republicans.

Driving the news: Haley's campaign has been rebutting the perception that New Hampshire could be her best performance.

• "Nikki's been up against this before. No one in South Carolina thought she had a chance," a letter Tuesday from her campaign manager said. "The entire political class — including many who are now supporting Donald Trump — lined up against her."

The latest: The lead strategist for super PAC SFA Fund, Mark Harris, further set expectations in New Hampshire on Tuesday afternoon.

• "We were right around 20[%] in Iowa," he told reporters. "We're gonna do much better than that tonight. That is success."
• Read more ... Go deeper: Nikki Haley allies bank on big independent push in New Hampshire

Phillips' lonely campaign cuts deeper at Biden's age

The Minnesota Democrat running a long-shot campaign sharpened his attacks in the final days before Tuesday's primary, Axios' Alex Thompson reported from Manchester.

Why it matters: Phillips' increasingly pointed attacks will be fodder for Republicans to use against Biden in a general election.

• Phillips, 55, told Axios that it would be "impossible" for Biden to do the job for four more years. (Biden would turn 85 in the third year of another term.)

Between the lines: Phillips, who entered the race in late October, has been lowering expectations for his performance in New Hampshire despite investing most of his time and money in the state.

Read more from the interview ... Go deeper: Why Bernie's ex-campaign boss is helping Dean Phillips challenge Biden

Biden campaign event interrupted by protesters

Biden appeared with Vice President Harris at a rare joint rally in Virginia on Tuesday focused on abortion rights, Axios' Natalie Daher writes.

• The event fell only a day after the anniversary of the overturned Roe v. Wade decision.
• Biden has been been highlighting his administration's efforts to protect reproductive rights as Democrats bank on the salience of abortion protections to drive voter turnout.

Protesters interrupted the event at least a dozen times, NBC reported.

• They called him "Genocide Joe" and called for a ceasefire in Gaza.
• The president has faced increasing pressure over his handling of the Israel-Hamas war.

Go deeper on Biden's abortion ambivalence.

Trump teases VP pick (again)

Trump left the door open Tuesday to selecting Sen. Tim Scott (R-S.C.) as a potential running mate in 2024 if he is the Republican nominee, Axios' Erin Doherty reports.

Driving the news: "He's a guy that I look at," Trump said in an interview on "The Howie Carr Show."

Zoom in: Scott, who suspended his presidential campaign last year, endorsed Trump in the GOP primary last week in a blow to Haley, who appointed Scott to the Senate when she was South Carolina governor.

• Trump also suggested during the radio interview that he did not expect Haley to concede Tuesday.
• "We're just going to win, we're going to keep winning," Trump said.

What to watch: Trump teased the timing of his vice presidential pick over the weekend, saying he "may or may not release something" over the next couple of months.

• "There's no rush to that — it won't have any impact at all," he told Fox News.

Haley tears into Trump's "fellas"

Haley has been dropping not-so-subtle reminders that she is the only woman in the GOP presidential race, Axios' Sophia Cai reports from Manchester.

Why it matters: While she is not asking voters to choose her because she is a woman, Haley uses the phrase "fellas" to brush off the behavior of her male opponents, shrug off unfavorable endorsements and set herself apart.

• "There were 14 people in this race, a lot of fellas. All the fellas are out, except for this one," she said referring to Trump after Florida Gov. Ron DeSantis dropped out over the weekend.

Read more on the "fellas" mentions.

Trump complains about New Hampshire's primary rules

Trump in the lead-up to Tuesday repeatedly falsely claimed that New Hampshire Democrats would be able to vote in the Republican primary, Axios' Erin Doherty writes.

Driving the news: As recently as Tuesday evening, Trump called it "ridiculous" that New Hampshire allows voters to choose which primary they want to vote in.

Reality check: Voters in New Hampshire can only vote in a party primary if they are a member of that party or an independent, known as "undeclared," voter.

• The last day for a registered voter in New Hampshire to change their party affiliation was October 6, 2023, per the Secretary of State's website.
• Independent voters, which could be key to a strong Haley finish in New Hampshire, must choose whether they will vote in the state's Democratic or Republican ballot when they vote. They cannot vote in both primaries.

Shrunken GOP field on display in N.H.

The GOP primary is essentially a two-person race between Trump and Haley, after Florida Gov. Ron DeSantis suspended his campaign over the weekend, Axios' Erin Doherty writes.

The big picture: The Republican primary field at its largest saw more than a dozen presidential hopefuls vying for the nomination.

• DeSantis, former Arkansas Gov. Asa Hutchinson, entrepreneur Vivek Ramaswamy and former New Jersey Gov. Chris Christie all dropped out this month.

Zoom on: Biden, the likely Democratic nominee, has drawn long-shot challenges from Democrats including Phillips and self-help author Marianne Williamson.

• Spoiler candidates have also brought an edge to primary season.

N.H. voter sees Haley as "only viable option"

In Tilton, N.H., election officials were closing up their polling site Tuesday evening after 1,100 people voted, Axios' Sophia Cai reports.

• The old mill town voted for Obama in 2012 and then Trump in 2016. It's now known for its shopping mall and the ocean buoys it produces.
• "I disliked Joe Biden, and I hate Donald Trump. So the only viable option for me was Nikki Haley," Joseph Jesseman, a 70-year-old chef, told Axios. "I hope Haley does well here."

Pic: Disgraced ex-Rep. Santos at Trump party

Haley's got a Trump problem in South Carolina

One big reason that Haley had so much riding on New Hampshire: Trump is dominating the polls and the endorsement race in her home state of South Carolina, which holds its GOP primary on Feb. 24, Axios' Erin Doherty reports.

Why it matters: The Trump campaign has built a powerful firewall using many politicians who'd otherwise be expected to back Haley — and he's already started to flex the advantage.

Driving the news: Reps. Nancy Mace and Jeff Duncan this week became the latest South Carolina Republicans to fall in line behind Trump.

• Rep. Ralph Norman is the only Republican member of Congress from South Carolina who backed Haley. She's also won a number of endorsements from members of the South Carolina state legislature.

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Vibes at Haley watch party: "God is so good"

Haley thanked New Hampshire voters at her watch party in Concord, N.H. Tuesday for a "great night," Axios' Sophia Cai reports from the scene.

• "The best way you appreciate your blessings is to get back," the former South Carolina governor added, thanking her family for support.
• She congratulated Trump on his victory: "He earned it."

"Now you've all heard the chatter among the political class. They're falling all over themselves saying this race is over," she said.

• The crowd erupted: "It's not over!"

"This race is far from over," she said. "There are dozens of states left to go. The next one is my sweet state of South Carolina."

• Don't forget: Nevada is up next. Haley is only on primary ticket, which won't award delegates.

Trump makes GOP primary history with projected victory

The final margin of Trump's projected victory is not yet known, but he's already made some primary history, Axios' Erin Doherty writes.

Driving the news: Trump's back-to-back victories in the Iowa caucuses and New Hampshire make him the first non-incumbent Republican candidate in modern history to win both contests, per Politico.

• No Republican candidate has won both contests and not wound up as the party's nominee, per NBC News.

Trump sends fundraising missive off N.H. win

Some 15 minutes after AP projected his win, former President Trump sent out a fundraising email titled: "This race is over!"

• "THIS RACE IS OVER!" Trump said in the email, Axios' Bec Falconer writes.
• "I just won the New Hampshire primary, and I delivered BACK TO BACK landslide victories."

He thanked his supporters who've stood by him during his four criminal indictments and other legal woes before declaring: "I am the only person that can STOP JOE BIDEN" and appealing for donations.

• On Truth Social, the former president wrote: "Haley said she had to WIN in New Hampshire. SHE DIDN'T!!!"
• He went on: "DELUSIONAL!!!"

Biden campaign: Trump "all but locked up" GOP nomination

The Biden campaign in a statement Tuesday night called out the "election denying, anti-freedom MAGA movement" after Trump won the New Hampshire GOP primary, Axios' Natalie Daher writes.

• The statement left out the president's win via a write-in campaign, which grassroots organizers have run.
• "Trump is offering Americans the same extreme agenda that has cost Republicans election after election: promising to undermine American democracy," Biden-Harris 2024 campaign manager Julie Chávez Rodriguez said.

Biden has returned to familiar territory with his re-election campaign messaging, this time also emphasizing the Jan. 6 insurrection.

• Go deeper: Why Obama, Dems fear Biden complacency

Congressional GOP rushes to crown Trump

Trump picked up several new endorsements from GOP lawmakers on Tuesday night, including statements by top House Republicans calling on Haley to drop out, Axios' Andrew Solender reports.

• "It's now past time for the Republican Party to unite around President Trump," House Speaker Mike Johnson (R-La.) said in a statement.
• House Republican Conference Chair Elise Stefanik (R-N.Y.) released a statement calling for Haley to "suspend her failing campaign and unite behind President Trump."

Zoom out: The campaign chiefs for both House and Senate Republicans also called for the party to coalesce around Trump.

Trump appears with Scott, Ramaswamy during victory speech

Trump branded his post-win remarks as "not your typical victory speech," while angrily making repeated, pointed attacks against Haley, Axios' Erin Doherty writes.

Driving the news: "Let's not have somebody take a victory when she had a very bad night," he said.

• Another target: GOP Gov. Chris Sununu of New Hampshire, a sharp Trump critic who endorsed Haley.

"Who the hell was the imposter that went up on the stage before ... and like claimed a victory?" Trump said of Haley, at a point when his projected lead was about ten points.

Between the lines: Trump was joined on stage by former GOP presidential rivals Sen. Tim Scott (R-S.C.) and entrepreneur Vivek Ramaswamy, in addition to members of his family.

• Speaking to Scott, a fellow South Carolinian with Haley who recently backed the former president, Trump said: "You must really hate her."
• "I just love you," Scott said in response.

What to watch: The former president also previewed the Feb. 24 South Carolina primary, which Haley signaled during her remarks she is already preparing for.

• "I did hear Nikki say and now it's off to South Carolina. Well, I love South Carolina," he said.
• He twisted the knife, as he's leading in the polls in Haley's home state.