“I am appalled that you would begin a presidential debate on a topic like this,” Gingrich said with great outrage after CNN’s moderator, John King, asked (rather politely I thought) whether he had any response to Marianne Gingrich’s interview with ABC News and The Post. Gingrich said that bringing up the issue “is as close to despicable as anything I can imagine.” For good measure, he called the media “destructive, vicious, negative.”

He also said, “I am tired of the elite media protecting Barack Obama by attacking Republicans.” Bringing a question about his personal life around to Obama was quite a reach, yet Gingrich knew that his statement would be taken as gospel by most of the conservative voters he is trying to reach. And he flatly denied he had requested an open marriage. “The story is false,” he said.

My hunch is that Gingrich’s performance tonight will keep his momentum in South Carolina going. For a great many Republicans, his attack on the media will outweigh the impact of the open marriage story. Yes, Marianne Giungrich’s interview may push some evangelical voters Rick Santorum’s way — and it’s worth noting that Gingrich has been far weaker in the polls among women than men. But many who are moving to Gingrich have probably already discounted his past. And Rick Perry showed a shrewd understanding of the importance of repentance and redemption in evangelical theology. “The fact is, there is forgiveness for those who seek God,” Perrry said when he endorsed Gingrich, “and I believe in the power of redemption, for it is a central tenet of my own Christian faith.”

If Gingrich pulls out a victory in South Carolina, it will be because of this week’s two debates - and because Mitt Romney had once of the worst weeks of his campaign. Romney has made one mistake after another in talking about his taxes and his earnings. He is still tone deaf on matters related to economic class and his own financial situation. It was not the way a candidate wants to close a campaign.

Romney was better tonight than he was in the week’s earlier debate. His casting himself as an outsider when Gingrich and Santorum got inveigled in a very Washington argument about what the former Speaker had and had not done worked pretty well. But Romney continued to hurt himself by giving indeterminate answers to questions about whether and when he would release his tax returns. Some in the crowd actually booed him.

He faced one of the toughest set of challenges he has confronted for his switch on the abortion issue. And he took some hard knocks on the Massachusetts health care plan from Rick Santorum. Romney’s position on health care is not sustainable. When he defends the Massachusetts health plan, he is essentially defending the idea behind President Obama’s health plan. Yet he follows this up with a promise to repeal “Obamacare.” This doesn’t work for either supporters or opponents of the Affordable Care Act.

Rick Santorum was in good form, raising the fundamental question about Gingrich - whether he can be trusted as a leader - and leading the attack on Romney on health care. I thought Santorum was rather persuasive in casting himself as the less flashy guy who’d be solid and trustworthy. It was exactly the right argument for the candidate who has the lowest negatives and the least baggage of the top three. His problem is that he is now fighting a Gingrich tide that may have grown too strong for him to overcome.

Ron Paul had to fight his way into the discussion, joking it was odd that even though he is a physician, he was almost kept out of the discussions of both health care and abortion. In past debates, Paul has been quite effective in his attacks on Gingrich and Santorum. He had less of an impact tonight, perhaps because he had fewer opportunities.

Much has changed in just 36 hours. Gingrich, Santorum and Perry started the week tearing at each other in what looked like a fight for second place. Now Perry is out, and his ads attacking Gingrich and Santorum are off the air. Gingrich moved from far behind to within striking distance of Romney - and, in at least three polls, is narrowly ahead of him. This has the feeling of a Gingrich resurrection, his second in this campaign. The only good news for Romney is if he were to manage a narrow win, it will now look like a real victory..

Oh, yes, and will someone explain why nearly everyone -- I was not among them -- accepted that Romney had “won” the Iowa caucuses even though his eight-vote margin came under almost immediate question? Romney got credit for a “victory” for a critical 16 days. Will Santorum get any credit now that we know he’s won the thing by a whopping margin of 34 votes?

More from PostOpinions:

Petri: Gingrich grandiose, Romney terrible in debate

Rubin: Gingrich’s arm-twisting on Medicare

Rogers: How Gingrich channeled Tiger Woods