Chris Christie, the former governor of New Jersey who was eclipsed by Donald J. Trump in the 2016 presidential primaries, announced on Tuesday that he would seek the 2024 Republican nomination, setting up a rematch with the former president and expanding the field of G.O.P. candidates.
In making a second run for the presidency, Mr. Christie, 60, has positioned himself as the person most willing to attack both Mr. Trump, his former friend turned adversary, and Gov. Ron DeSantis of Florida, who has been in second place in nearly every public Republican primary poll for months.
Mr. Christie, who declared his run on Tuesday evening at a town-hall-style event in New Hampshire, set himself apart from all other Republicans running by going directly after Mr. Trump. He called him “a bitter, angry man,” said his record in office was a failure and, in an unusually personal attack, accused Mr. Trump and family members of profiting off the presidency, referring to an investment from the Saudi crown prince.
“The grift from this family is breathtaking,” Mr. Christie said. “It’s breathtaking. Jared Kushner and Ivanka Kushner walk out of the White House and months later get $2 billion from the Saudis?”
“That’s your money he stole,” he continued, adding, “That makes us a banana republic.”
Over more than two hours, Mr. Christie also chided other Republicans in the race as being too timid to criticize Mr. Trump by name. Describing a recent appearance in Iowa of other 2024 hopefuls, he mocked their euphemistic swipes at the former president. “‘We need a leader who looks forward, not backwards,’” Mr. Christie said, his voice dripping sarcasm. “I get it! You’re talking about the way the 2020 election was stolen. And you won’t say it wasn’t stolen.”
In earlier appearances, Mr. Christie has called Mr. Trump a loser because of his 2020 defeat, and said that he was unfit to return to the White House after inciting a mob to attack the Capitol on Jan. 6, 2021. Mr. Christie has said that if Mr. Trump is the nominee, he will not vote for him.
Still, with polls showing Mr. Christie to be the most unpopular 2024 candidate among Republican voters, the existential question for his race is, Who will he appeal to?
The audience on Tuesday, at the New Hampshire Institute of Politics, appeared to be almost entirely independent voters. Registered Republicans were hard to find. In interviews, almost everyone disapproved of Mr. Trump, which suggested that Mr. Christie could activate a small but passionate group of supporters.
“He’s a very capable guy,” Paul R. Kfoury Sr., a retired judge from Bedford, N.H., said of the former governor. “Very centrist. Not a right-wing nut like so many of them, frankly, if I may be candid.” But he was skeptical of Mr. Christie’s chances in his party. “It’s a heavy lift,” he said.
New Hampshire’s many independents could play a crucial role in the 2024 Republican primary because there is unlikely to be a competitive Democratic race.
Carolyn Cicciu, 77, from Goffstown, N.H., voted for Joseph R. Biden Jr. in 2020 “because I had no choice,” she said. Now, she said she had concerns about Mr. Biden’s age.
“Whatever candidate I choose, I want it to be somebody that is not so partisan that they can’t see what’s good about the other side’s position,” added Ms. Cicciu, a retired middle-school teacher.
Mr. Christie has said he sees a path to the nomination and is not running merely as a “paid assassin” to take on Mr. Trump for the benefit of other candidates.
On Tuesday, he cited political punditry about his candidacy in a mocking voice: “Christie doesn’t really care about winning, all he cares about is destroying Trump,” he said. Then he added: “How are those two things mutually exclusive?”
“Let me be very clear,” he said. “I am going out there to take out Donald Trump, but here’s why: I will win. And I don’t want him to win.”
Still, Mr. Christie’s path to securing the nomination is complicated. He is a northeastern Republican who has not been enmeshed in the culture wars of the Trump era. His main path would necessarily be through New Hampshire, a state where he waged a fierce campaign in 2016 but ultimately came up short. And to gain traction, he will need to rely on attention from candidate debates.
His campaign will depend heavily on media coverage and a nimbleness to travel to places where that is likeliest. New Hampshire is the state where he will begin his campaign, but not necessarily where he will hunker down.
He still needs to meet the criteria set by the Republican National Committee to get on that debate stage, which includes 40,000 unique donors.
Yet if he makes it, as a onetime friend of Mr. Trump, he has a keen understanding of the former president and how to get under his skin. Depending on how the race goes, Mr. Christie’s main impact could be in badly damaging Mr. Trump, whom he has been attacking with gusto. But he has been encouraged by a number of Republican donors and senior officials in recent weeks, particularly as Mr. DeSantis stumbled before even becoming a formal candidate.
Mr. Christie, a former federal prosecutor, will be in a unique position to attack Mr. Trump’s various legal travails, as he is the first former president to be indicted and is facing the potential for additional indictments in other cases.
Still, Mr. Christie will face questions about his conversion from Trump supporter to detractor. (Mr. Trump, after leaving office, referred to Mr. Christie as “an opportunist.”)
Mr. Christie was a favorite of some Republicans to run for the nomination in the 2012 campaign, when he was one of the country’s most famous governors, known for tangling with union leaders and selling himself as knowing how to balance a budget. But instead of running that year, while his star was rising, he chose to focus on running for re-election, receiving national attention for his response during the devastating Hurricane Sandy — and criticism from some Republicans for appearing with President Barack Obama in New Jersey days before the election at an event related to the storm’s aftermath.
The anger among Republicans presaged a political environment in which Republicans punished their elected officials for comity with Democrats.
By the time Mr. Christie announced he was running for president in 2015, his candidacy had been hobbled by the so-called Bridgegate political revenge scandal that swamped his administration two years earlier. Mr. Christie denied involvement in the alleged payback scheme involving closing lanes on the George Washington Bridge to get back at a political opponent of the governor, and convictions against two defendants were overturned in 2020 by the U.S. Supreme Court. But by then, Mr. Christie’s political fortunes had been damaged.
Asked by an attendee on Tuesday about his biggest mistake in public life, he cited Bridgegate. Without accepting direct responsibility, he called it a “fraternity prank” by people who reported to him. “It cost me a lot,” he said. “It cost me credibility. It humiliated me.”
After dropping out of the 2016 race, Mr. Christie endorsed Mr. Trump that February, one of the first prominent national Republicans to do so. That endorsement was valuable to Mr. Trump as he tried to appeal to Republicans who were skeptical of him over his comments calling for a ban on Muslims entering the country, or his misogynistic statements about the Fox News host Megyn Kelly.