He said he was "tired of the elite media protecting Barack Obama" by attacking his potential Republican opponents. That won a standing ovation though it was hard to immediately judge whether he had succeeded in defusing the issue among the Palmetto State's conservative voters.
Santorum, a former Pennsylvania senator, said he was grateful for God's forgiveness but indicated the topic was legitimate: "What we did in our lives are issues of character."
Texas Rep. Ron Paul noted that "my wife of 54 years is with me tonight."
Romney's brief comment: "Let's get on to the real issues."
As the debate continued, Romney and Gingrich did turn their fire on one another, vying for advantage and questioning the other's electability. The exchanges were tumultuous because the stakes were high: The outcome of the South Carolina primary Saturday and, perhaps, the course ahead of the Republican presidential race.
Gingrich demanded that Romney provide more information and defense of his tenure at Bain Capital, the private equity firm he founded. Gingrich said some of the corporate takeovers had made it harder for the companies to survive and cost jobs.
Romney accused Gingrich of adopting tactics he expected to come from Democrats. "I know we're going to get attacks from the left, from Obama, on capitalism," the former Massachusetts governor said. "My view is that capitalism works. Free enterprise works." When Obama makes similar arguments, he vowed, "We're going to stuff it down his throat," making the case that it's "capitalism and freedom that makes America strong."
Speaking in general terms, he defended his previous statements that the firm's work resulted in the creation of more than 100,000 jobs.
Meanwhile, Santorum accused Romney and Gingrich of "playing footsies with the left" by supporting health care proposals that included mandates requiring people to have insurance, a provision of the health care overhaul Obama signed in 2010.
Santorum also attacked Gingrich for his leadership of the House, which Gingrich disputed. Romney then cited the exchange as "a perfect example of why we need to send to Washington [someone] who has not lived in Washington."
Several polls released Thursday showed Gingrich narrowing Romney's double-digit edge in the state after a strong performance in a debate Monday in Myrtle Beach. An NBC News/Marist Poll showed Romney at 34 percent, ahead of Gingrich, by 10 percentage points, but his advantage had been cut in half by Tuesday, the last day of polling. On Monday, before the debate, Romney had led by 15 points.
A Politico poll put Romney at 37 percent, seven points ahead of Gingrich. Texas Rep. Ron Paul finished third and former Pennsylvania senator Rick Santorum fourth in both surveys.
If Gingrich wins, he would pierce the aura of inevitability that the Romney camp has fostered. He could gain the momentum and money to wage a campaign for the Florida primary on Jan. 31 and the contests to follow.
A Romney win would reinforce a perception that he has emerged from the early contests including South Carolina, where the political terrain doesn't favor him to be the presumptive nominee.
Some Republicans raised red flags about Gingrich as a potential nominee.
"As Gingrich rises, it returns voters' focus to the same issues that derailed him in Iowa: questionable character, temperament and judgment that could trump his penchant for big ideas and raise serious questions about his viability against President Obama," says Jim Dyke, a GOP strategist based in Charleston who hasn't endorsed a candidate. "Part of his resurgence is credited to his ability to put any negatives on the media or the Romney campaign but his inability to dispute almost any of them suggests he would be cat food for a lioness Obama campaign."
If Romney ends up winning Saturday, he'll move "from the rough seas to calm waters," says Chip Felkel, a Republican strategist based in Greenville, S.C., who isn't affiliated with a candidate. "Right now he's got some high waves and they've done a lot of it to themselves. His team how they didn't have him prepared for those questions on taxes, I'll never know."
Felkel's not predicting what will happen Saturday. "It's very scrambled right now."