U.S. Rep. Lauren Boebert defended her mountains-to-plains shift in congressional districts, even as Republican rivals used the contest's first debate Thursday night to suggest she is a carpetbagger and hypocrite.

Why it matters: How voters perceive Boebert's move will determine whether she can win in the 4th District, and the debate offered the first test of her new campaign.

State of play: Her move out of her difficult re-election contest in the 3rd District to compete in the deep-red 4th District drew the most attention at the Fort Lupton debate.

She addressed it at the start, announcing she just moved to the area and signed a lease for a home in nearby Windsor. "I am here to earn your vote. This is not a coronation," she said.

"The crops may be different in Colorado's 4th District, but the values are not," she added.

Yes, but: The remark did little to quell the questions. None of the eight other candidates on stage said they would support Boebert if they weren't running and she placed fifth in an informal straw poll.

"Can you give the definition of 'carpetbagger' to me?" state Rep. Mike Lynch asked Boebert at one point.

"My boys and I needed a fresh start," she responded, referring to her divorce and family issues.

The intrigue: The open animosity reflects a Republican primary that is devolving into a clown-car crash.

Between the lines: Six candidates acknowledged in the debate that they were once arrested, and four of the most prominent candidates are marked by controversies.

Boebert's personal life is making headlines, and she had to apologize for causing a disturbance and being removed from a "Beetlejuice" performance in Denver.

Lynch resigned his post as the House Republican leader earlier this week after facing pressure from his party for trying to hide a DUI arrest and gun charges.

Anti-abortion state Rep. Richard Holtorf admitted in a recent speech that he helped pay for a girlfriend to get an abortion, saying it helped her "live her best life."

Ted Harvey, a former state lawmaker, has come under scrutiny for running a "scam PAC" that spent more on operating costs and salaries than a pro-Trump campaign.

What they're saying: "People are human and make mistakes," Lynch said, referring to his arrest. "It's not how you get knocked down or the mistake, it's how you get back up on your feet."

The other side: Deb Flora, a conservative radio host, chastised her rivals, saying the party's nominee needs to "live on the principles we are standing on."