Mr. Christie, a onetime star presidential recruit who finished in sixth place in New Hampshire in 2016, has become a fierce Trump critic.
Former Gov. Chris Christie of New Jersey, who announced a second campaign for president on Tuesday after a disappointing run in 2016, has had a roller coaster of a political career in more ways than one.
In the span of four years, he went from star presidential recruit to scandal-dogged sixth-place finisher in New Hampshire. In the next seven, he went from serving as one of Donald J. Trump’s most influential advisers to advertising himself as the only candidate brave enough to denounce Mr. Trump to his face.
Here are five things to know about Mr. Christie.
He had a meteoric rise in his first term as governor …
Mr. Christie first drew national attention in 2009, when he was elected governor of New Jersey over a Democratic incumbent, Jon Corzine.
He quickly notched legislative victories for Republicans in a Democratic-leaning state, including passing a major overhaul of New Jersey’s public employee pension system.
Making use of a tactic that is now commonplace but was more striking at the time, he also attacked critics at public events — in 2012, he told a law student who had heckled him that if “you conduct yourself like that in a courtroom, your rear end’s going to be thrown in jail, idiot.” His showmanship and combativeness made him appealing both to Republican voters and to party operatives, who began urging him to run for president in 2012.
He didn’t, choosing instead to give the keynote address for Mitt Romney at the Republican National Convention, become the chairman of the Republican Governors Association and establish himself as an early front-runner for 2016.
His profile rose further after his management of the state’s recovery from Hurricane Sandy in 2012, when he famously welcomed President Barack Obama to New Jersey — an image that infuriated some Republicans but helped cement Mr. Christie’s reputation as someone who could switch modes from attack dog to bipartisan statesman as needed.
… and a ‘Bridgegate’-fueled crash in his second term.
If Mr. Christie’s first term as governor was politically triumphant, his second term was politically calamitous because of a scandal that became known as Bridgegate.
In September 2013, not long before Mr. Christie was up for re-election as governor, high-ranking officials at the Port Authority of New York and New Jersey, which operates bridges and tunnels between the two states, closed two of three lanes onto the George Washington Bridge from Fort Lee, N.J. The closings caused chaos.
The ostensible rationale was to study traffic patterns. But it soon emerged that a Christie ally at the Port Authority had ordered the closings as part of a scheme to punish the mayor of Fort Lee for not endorsing the governor’s re-election campaign — and that he had done so after Mr. Christie’s deputy chief of staff emailed him, “Time for some traffic problems in Fort Lee.” In a trial in 2016 against the deputy chief of staff and a Port Authority official, a witness testified that Mr. Christie himself had been told of the political reason for the closings while they were happening, and had laughed.
Mr. Christie denied involvement in the scandal, but it consumed his second term and proved a serious liability in his first presidential campaign. By the time he left office, he had the lowest approval rating recorded for any New Jersey governor.
A campaign event in New Hampshire for Mr. Christie’s 2016 presidential run. Mr. Christie never gained much traction then — against any of his competitors, much less Mr. Trump.Credit…Ian Thomas Jansen-Lonnquist for The New York Times
His 2016 campaign served to knock out Marco Rubio.
Mr. Christie first ran for president in 2016, a year that made mincemeat of quite a few Republicans seen as rising stars in the party, and he was no exception.
He never gained much traction — against any of his competitors, much less Mr. Trump — and came in sixth in the New Hampshire primary after focusing his efforts there. He dropped out the next day.
But Mr. Christie did have a significant impact on the trajectory of the Republican race, just not to his own benefit.
He helped pave the way for Mr. Trump’s nomination by wounding the man who had looked to be his strongest opponent: Senator Marco Rubio of Florida.
In a debate in New Hampshire in early February, Mr. Christie went after Mr. Rubio mercilessly — accusing him of being inauthentic and relying on canned lines, a criticism Mr. Rubio lent credence to by responding with canned lines. (“There it is, everybody,” Mr. Christie replied.) The attack was so effective that the debate audience began to boo Mr. Rubio.
Mr. Christie and Donald Trump ahead of a Trump rally in 2016.Credit…Mark Makela for The New York Times
He was a member of Trump’s inner circle for years …
After ending his own campaign, Mr. Christie quickly endorsed Mr. Trump, praising him for “rewriting the playbook of American politics.” His endorsement was a big deal given that most of the Republican establishment was still trying to find anyone other than Mr. Trump to coalesce around.
Mr. Christie became a highly influential adviser to the Trump campaign. In characteristically combative fashion, he defended Mr. Trump even when he went too far for other Republicans.
Implicit in the alliance was that Mr. Christie would get a high-ranking job in the Trump administration, perhaps even the vice presidency. But while Mr. Trump chose him to lead his presidential transition team and offered him cabinet posts, Mr. Christie did not get the job he really wanted: attorney general.
Even so, he stayed loyal, helping Mr. Trump with debate preparation in 2020. He did not break away until Mr. Trump tried to overturn his election loss — at which point Mr. Christie began speaking forcefully, including in a book.
Mr. Christie greets voters and students at the New Hampshire Institute of Politics at Saint Anselm College in Manchester, N.H., earlier this year.Credit…Holly Ramer/Associated Press
… but has reinvented himself as Trump Enemy No. 1.
Mr. Christie is pitching himself as the only candidate willing to confront Mr. Trump head-on. (Though Gov. Ron DeSantis of Florida has begun to do that, other candidates largely have not, lest they alienate the pro-Trump Republican base.)
In a pre-campaign stop in New Hampshire in March, Mr. Christie tried to convince voters that he was the man to do this by evoking his long-ago brawl with Mr. Rubio: “You better have somebody on that stage who can do to him what I did to Marco,” he said.
Voters remain unconvinced. In a recent Monmouth University poll, Mr. Christie was the only candidate or potential candidate with a net-negative approval rating among Republicans — only 21 percent of whom viewed him favorably, compared with 47 percent who viewed him unfavorably.
Mr. Christie said in New Hampshire in April: “I don’t think that anybody is going to beat Donald Trump by sidling up to him, playing footsie with him and pretending that you’re almost like him.”
But the fact that he supported Mr. Trump throughout his presidency went unmentioned until a teenager asked a question: Given his denunciations of Mr. Trump for undermining democracy, did he still believe Mr. Trump had been a better choice than Mrs. Clinton?
“I still would’ve picked Trump,” Mr. Christie acknowledged.