White House hopeful Newt Gingrich weathered a pummeling by rivals who attacked the Republican frontrunner's conservative credentials, marital infidelities and a provocative remark about Palestinians.
But the former House speaker coolly defended his most controversial views in a feisty debate on Saturday night, including a recent remark calling Palestinians an "invented people," while conceding that voters will have to decide whether he is fit to be president.
Meanwhile, Mitt Romney, fighting to regain the Republican lead, appeared to have run in to trouble of his own making, by challenging Texas governor Rick Perry to a $10,000 bet in a heated moment of the debate.
Supporters of the former Massachusetts governor went on talk shows on Sunday to try to douse the morning after controversy, while banging away at Gingrich.
"He used a figure of speech," said former New Hampshire governor John Sununu, a Romney backer, pooh-poohing suggestions that the large bet added to perceptions that the wealthy former venture capitalist was out of touch with ordinary Americans.
"I think the only thing that will come out of that is remind people about a $500,000 outstanding bill at Tiffany's," Sununu said on CNN, referring to a revolving line of credit that Gingrich once had at the posh jewellery store.
"Those are not the things you should judge whether somebody should be president," he said.
There now is less than a month to go before it becomes the first state to nominate a Republican candidate to run against Democratic President Barack Obama.
Largely rural, midwestern Iowa is key to narrowing the field in the presidential nominating contests, and even seemingly insignificant slips can knock a candidate off stride in what has been a volatile race.
Perry, who saw his own lead evaporate after choking in early debates, said on Sunday he was "taken a little aback" when Romney wanted to bet him on the truth of a claim Perry made about Romney's changing position on health care insurance.
No one in Iowa "would even think about that a $10,000 bet was possible. So, a little out of touch with normal Iowa citizen," he said.
Gingrich, for his part, also had supporters on talk shows playing defence after a performance that got generally favourable reviews in the US media.
"Newt's done well at the debates," Rick Santorum, a former senator who has lagged in the rear of the Republican field, grudgingly acknowledged on CNN.
"I think that's been his forte. His forte is glib."
Written off as politically dead months ago, Gingrich surged to the front of the pack in recent weeks as early contenders Perry and Herman Cain saw their support collapse amidst blunders and sex scandals.
Polls this week show Gingrich with a significant lead over Romney, who had been seen as having the party's best chance of beating Obama in 2012 despite his inability to win over the party's conservative base.
Perry, who is wooing the party's conservative base in hopes of reviving his flagging campaign, fired the sharpest rebuke of Gingrich.
"I've always been of the opinion if you cheat on your wife, you'll cheat on your business partner. So I think that issue of fidelity is important," Perry said.
Gingrich said he thinks infidelity is "a real issue" and admitted having "made mistakes at times."
"I think people have to measure who I am now and whether I'm a person they can trust. All I can tell you is I am delighted at the way people have been willing to look at who I am, to look at what my record has been," he said.
When slammed by his rivals for saying in an interview with the Jewish Television network that the Palestinians were an "invented people," Gingrich refused to back down.
"The Palestinian claim to a right of return is based on a historically false story," he insisted, adding: "These people are terrorists. They teach terrorism in their schools."
"I think sometimes it is helpful to have a president of the United States with the courage to tell the truth," Gingrich said.
"Just as it was when (Ronald) Reagan went around his entire national security apparatus to call the Soviet Union an evil empire."
Gingrich currently has the support of 27 to 33 per cent of likely Republican voters both nationally and in Iowa, while Romney's support ranges from 16 to 23 per cent.
Gingrich has also narrowed Romney's robust edge in New Hampshire, which votes on January 10, and is ahead of him in South Carolina and Florida, which vote on January 21 and January 31, respectively.