Former New Jersey Gov. Chris Christie, a top GOP Trump critic, launches 2024 presidential campaign

Former New Jersey Gov. Chris Christie announced he is running for president, injecting a dose of anti-Trump criticism into a Republican primary field that has largely been reluctant to cross its leading candidate.

Speaking without a script at a town hall event in Manchester, New Hampshire, Christie called out the former president by name as he spoke at length about what he saw as a crisis of leadership at a critical moment in American history.

"A lonely, self-consumed, self-serving mirror hog is not a leader," Christie said.

"The person I am talking about who is obsessed with the mirror, who never admits a mistake, who never admits a fault," Christie then clarified, "is Donald Trump."

Christie also appeared to acknowledge that he is considered a long shot in the Republican primary, where Trump and Florida Gov. Ron DeSantis are the clear front-runners.

"I'll say to you tonight that I can't guarantee you success in what I'm about to do. But I guarantee you that by the end of it you'll have no doubt in your mind who I am and what I stand for and whether I deserve it," Christie said.

"I intend to seek the Republican nomination for president of the United States in 2024, and I want your support," he said.

Christie, 60, announced his campaign in the same state where his last presidential bid had come undone.

Christie placed sixth in that state's 2016 primary and dropped out of the race shortly thereafter. In a surprising move, Christie endorsed then-candidate Donald Trump just days later. He went on to help prep Trump for his debate against now-President Joe Biden in the 2020 contest.

But his support for Trump dried up soon after, as the former president, following his loss to Biden, fed his supporters a firehose of conspiracy theories and false claims of widespread voter fraud while pushing to overturn his defeat.

Like many Republicans, Christie criticized Trump after a violent mob of the then-president's supporters stormed the U.S. Capitol on Jan. 6, 2021, derailing the peaceful transfer of power to Biden. But while much of the GOP establishment softened its stance on Trump in the ensuing months, Christie kept up his criticism.

"I think he's a coward and I think he's a puppet of [Russian President Vladimir] Putin," Christie said last month in response to Trump's comments about the Ukraine war during a CNN town hall.

Christie, whose aggressive takedown of Sen. Marco Rubio in a 2016 Republican debate was a highlight of his campaign, has stressed the need for Trump's current challengers to forcefully confront him on the debate stage.

"You better have somebody on that stage who will do to him what I did to Marco, because that's the only thing that's going to defeat Donald Trump," Christie said in March.

"It's not going to end nicely no matter what," the former governor said of Trump. "His end will not be a calm and quiet conclusion."

Christie has suggested in recent months that he wouldn't run unless he sees a feasible path to victory. To many political watchers, that path remains unclear.

Polls of the prospective primary race show Christie garnering little support from Republican voters. A recent Monmouth University survey found Christie was the only declared or potential GOP candidate to receive a net negative favorability rating, 21% to 47%, from Republican voters.

Christie's announcement comes less than two weeks after DeSantis officially joined the Republican primary race, becoming the top non-Trump contender. South Carolina Sen. Tim Scott entered the primary that same week. Former Vice President Mike Pence joined the fray on Wednesday.

Allies of the former New Jersey governor recently launched a super PAC, Tell It Like It Is, to support his run for president.

Christie was elected governor of the historically blue state in 2009 and served for two terms, the maximum allowed under term limit rules.

He gained national attention in 2012 for his response to Superstorm Sandy, which battered his state and caused billions of dollars in damage. Christie's vocal praise for then-President Barack Obama's support amid the crisis angered some of his fellow Republicans, but the governor's polling numbers surged in the wake of the storm.

Those high approval ratings would crater by the end of Christie's second term, which was marred by his connection to the 2013 "Bridgegate" scandal.

In September of that year, commuter lanes were shut down on the George Washington Bridge connecting New Jersey and New York for several days in retaliation against a mayor who refused to back Christie's reelection bid. The lane closures caused massive traffic jams.

The Supreme Court in 2020 reversed fraud convictions against two of Christie's aides who had played key roles in the scandal.

Christie was succeeded by Democratic Gov. Phil Murphy, who won a second term in 2021. Christie joined ABC News in 2018 as a political contributor. In 2020, he was hospitalized with a severe case of Covid-19 that he said put him in an ICU for a week.