AMNA NAWAZ: The race to the Republican nomination for president is picking up, as a growing number of candidates jump into an already crowded field.

Former New Jersey Governor Chris Christie filed his paperwork with the Federal Election Commission today, becoming the latest to launch his presidential bid.

Tonight, he kicks off his run with remarks at a town hall in Manchester, New Hampshire.

Laura Barron-Lopez has more.

LAURA BARRON-LOPEZ: Chris Christie hasn't been shy about his soured feelings for Donald Trump.

FMR.

GOV.

CHRIS CHRISTIE (R-NJ): Donald Trump is a TV star, nothing more, nothing less.

If we put him back in the White House, the reruns will be worse than the original show was.

LAURA BARRON-LOPEZ: The former two-term governor from New Jersey officially kicks off his bid for president in New Hampshire, the same state where he finished in sixth place in the 2016 Republican primary and within 24 hours dropped his first bid for the presidency.

Then and now, he positioned himself as a no-holds-barred candidate, leaning into the tough-talking reputation he built his governor, but for roughly two decades, Christie considered Trump a friend and advised him throughout his 2016 campaign and presidency.

FMR.

GOV.

CHRIS CHRISTIE: I am proud to be here to endorse Donald Trump for president of the United States.

LAURA BARRON-LOPEZ: After serving in Trump's administration as chair of the Opioid and Drug Abuse Commission, Christie broke with him in 2020, as Trump spread misinformation about a stolen election.

He considers those lies a threat to the Republican Party.

FMR.

GOV.

CHRIS CHRISTIE: But I got off the train when he stood up in the West Wing of the White House, behind the seal of the president, and told us the election was stolen, when he didn't have one fact to back it up.

LAURA BARRON-LOPEZ: Since their fallout, Christie's also blamed the former president's rhetoric for the January 6 attack on the Capitol.

FMR.

GOV.

CHRIS CHRISTIE: I think everything that he was saying from election night forward incited people to that level of anger.

LAURA BARRON-LOPEZ: Now a presidential hopeful once again, Christie is positioning himself as Trump's foil, an alternative with his own accomplishments and a legacy of bipartisanship and moderate policy positions.

FMR.

GOV.

CHRIS CHRISTIE: I was a pro-life governor in New Jersey, which is one of the most pro-choice states in America.

JONATHAN KARL, ABC News: But you weren't attempting to ban abortion in New Jersey.

FMR.

GOV.

CHRIS CHRISTIE: I wasn't, but, Jon... (CROSSTALK) JONATHAN KARL: Your personal views... FMR.

GOV.

CHRIS CHRISTIE: I was very clear about my personal views.

LAURA BARRON-LOPEZ: From 2002 to 2008, he served as a federal prosecutor in New Jersey, carving out a tough-on-corruption reputation.

He then set his sights on the governor's mansion, elected in 2009.

FMR.

GOV.

CHRIS CHRISTIE: Hey, New Jersey, we did it.

(CHEERING AND APPLAUSE) LAURA BARRON-LOPEZ: During his first term, he was credited for his leadership and handling of recovery efforts after Hurricane Sandy.

FMR.

GOV.

CHRIS CHRISTIE: That's the only message I'm here to deliver is of support and let them know I'm on the job and we're going to continue to work real hard.

LAURA BARRON-LOPEZ: He went on to be reelected in 2013.

But his second term was marred with controversies, namely, the infamous highway traffic scandal known as Bridgegate.

One of Christie's aides and multiple political appointees colluded to create traffic jams in Fort Lee, New Jersey, by closing lanes to the George Washington Bridge, one of the busiest commuter bridges in the world.

FMR.

GOV.

CHRIS CHRISTIE: I have 65,000 people working for me every day.

And I cannot know what each one of them is doing at every minute.

But that doesn't matter.

I'm ultimately responsible for what they do.

LAURA BARRON-LOPEZ: The scandal became the subject of a federal investigation and ended in the indictments of Christie's deputy chief of staff and political appointees to the Port Authority.

Christie denied any direct involvement and was never charged, but the events cast a shadow on his time as governor.

In 2017, he was unapologetic after being photographed enjoying a holiday weekend on an empty beach he had closed to the public after a state government shutdown.

FMR.

GOV.

CHRIS CHRISTIE: The governor has a residence at the beach.

Others don't.

It's just the way it goes.

Run for governor, then you can have the residence.

LAURA BARRON-LOPEZ: He left office with a 15 percent approval rating down from a peak of 70 percent, one of the lowest of any governor in the history of New Jersey.

But Christie hopes to start fresh, a new chapter for himself and the party, as he takes on his former boss in the process.

For the "PBS NewsHour," I'm Laura Barron-Lopez.