Newt Gingrich defended himself against attacks from Texas Rep. Ron Paul and Minnesota Rep. Michele Bachmann as well as Mitt Romney, the former front-runner, in the first debate since he soared to the lead in polls nationally and in Iowa. The state's caucuses on Jan. 3 will kick off the competition for Republican National Convention delegates who will pick an opponent to President Barack Obama.
All six Republicans on stage assailed Obama's handling of the economy, the overriding issue of the election, yet split down the middle on legislation making its way toward a year-end vote in Congress to extend a Social Security payroll tax cut into 2012.
Here were some of the biggest moments of the night.
What's $10,000 among friends?
Mitt Romney challenged Texas Gov. Rick Perry's claims that the former Massachusetts governor backed a requirement that individuals purchase health care coverage.
"I'm just saying, you're for individual mandates, my friend," Perry told Romney during Saturday evening's debate, returning to a criticism that has dogged Romney's campaign.
"You've raised that before, Rick, and you're simply wrong," Romney responded, extending his hand toward Perry. "Rick, I'll tell you what, 10,000 bucks?"
It was a rich bet that perhaps reminded some voters that Romney has a fat enough bank account to make such wagers. But Perry wasn't playing.
"I'm not in the betting business," he said.
Romney's rivals seized on it. Democrats were giddy about the moment, which they planned to use to cast Romney as an elitist who could afford such lavish bets.
And aides to GOP hopeful Jon Huntsman — himself, the son of a famously wealthy family — announced they planned to criticize Romney on a website: www.10KBet.com.
Romney: Football Dreams Dashed
Former House Speaker Newt Gingrich also took on Romney, saying the only reason he wasn't a lifelong politician is because he came up short in his first campaign.
"Let's be candid: The only reason you didn't become a career politician is because you lost to Teddy Kennedy in 1994," Gingrich said to Romney.
"Now wait a second," Romney said.
"I'm just saying," Gingrich replied.
"It's a bit much: You'd have been a 17-year career politician by now if you'd won. That's all I'm saying on that one," Gingrich continued.
Romney lost his first campaign and returned to the private sector, where he made millions as a venture capitalist, and rescued 2002's Winter Olympics in Salt Lake City.
Romney, however, conceded Gingrich's suggestion — to a point.
"That's probably true," Romney said. "If I'd have been able to get in the NFL as I had hoped I could as a kid, why, I would've been a football star all my life, too."
Gingrich on Marital Infidelity: I'm a Grandfather Now
Gingrich also faced tough questions, including about his three marriages — including to wife, Callista, with whom he carried on an extramarital affair while still wed to wife No. 2.
"I think it is a real issue. I think people have to look at the person to whom they are going to loan the presidency," Gingrich said, while Callista Gingrich sat in the audience. "And they have the right to ask every single question."
Gingrich has previously acknowledged infidelity.
"I've made mistakes at times. I've had to go to God for forgiveness. I've had to seek reconciliation," he said Saturday evening. "But I'm also a 68-year-old grandfather and I think people have to measure who I am now and whether I'm a person they can trust."
Bachmann Keeps 9-9-9 Alive
Rep. Michele Bachmann was the first — and last candidate — on stage to bring up Herman Cain, who recently left the presidential race amid repeated accusations of sexual harassment and an extramarital affair.
It was likely part of a plan to lure some of Cain's supporters her way.
"One of our former competitors was Herman Cain, and he was always reminding us of the 9-9-9 plan," Bachmann said early on. "And what I'd like to do is the win, win, win plan."
She later praised Cain's contribution to the presidential race while answering her final question of the night.
Gingrich Defends 'Invented' Palestinians
Gingrich insisted that an interview where he called Palestinians "invented" was not a mistake. Romney said Gingrich was undermining Israel's Benjamin Netanyahu.
Gingrich insisted he was factually accurate when he said Palestinians were part of anti-Israel propaganda and that they were historically Arabs.
"Is what I said factually true? Yes," Gingrich said.
"I spoke as a historian," he said later.
"That was a mistake, on the speaker's part," Romney said of the interview with The Jewish Channel.
"The United States should not jump ahead of Bibi Netanyahu and say something that makes it more difficult for him to do his job," he added.
Other Key Moments
— Bachmann tried to link Romney with Gingrich — and paint both as unacceptable to conservatives on issues such as climate change and health care mandates. During one exchange, she branded the pair as "Newt Romney."
— Sen. Rick Santorum compared his record with Bachmann's — noting that he, too, fought as a member of the then-minority Republican caucus. His difference: He was able to win political fights, while Bachmann has come up short on her signature issues such as stopping Democrats' health care overhaul.
— Rep. Ron Paul took pride in often being the lone voice in Congress against legislation. "I end up sometimes, believe it or not, voting all by myself, thinking why aren't there people paying attention?" the Texan said.
— Huntsman was the evening's missing man. He did not meet the polling threshold to participate and instead campaigned in New Hampshire, a state he is making central to his strategy.
Based on reporting by the Associated Press.