Newt Gingrich may have succeeded in putting to rest for the moment concerns about his personal life with his decisive and confrontational answer at Thursday's debate -- a standout moment that secured his status as the field's most aggressive on-stage fighter. 

The former House speaker, who a day ago faced the prospect of a TV interview with his second wife undercut his chances in the South Carolina primary, appeared to make it a non-issue. 

He dressed down the moderator for leading the debate with a question about the interview, and his GOP opponents did not challenge him. 

Going into South Carolina's Saturday primary, Gingrich's opponents stayed virtually mum on the topic. Rick Santorum, who was Gingrich's chief critic Thursday night, said Friday only that "those issues are issues that people will look at." 

Gingrich on Thursday unequivocally denied the charge from his ex-wife Marianna that he sought an "open marriage" so he could carry on his relationship with Callista Bisek -- whom he eventually married. Though Marianne Gingrich told ABC News she stands by her claim, Gingrich said at the debate that the story is "false." 

And he turned the tables on the media, as he has in prior debates. 

"I am appalled that you would begin a presidential debate on a topic like that," Gingrich told the CNN moderator. "To take an ex-wife and make it, two days before the primary, a significant question in a presidential campaign, is as close to despicable as anything I can imagine." 

He added, "I am frankly astounded that CNN would take trash like that and use it to open a presidential debate." 

Gingrich now enters the South Carolina primary narrowly leading in most polls, after surging over the past week to overtake Mitt Romney

Romney's campaign, while steering clear of Gingrich's personal life, was trying a different approach on Friday. In retaliation for Gingrich's calls on Romney to release his tax returns, the Romney campaign called on Gingrich to release a more detailed accounting of the investigation into his ethical problems as House speaker, saying, "You know it's going to get out ahead of the general election." 

"Given Speaker Gingrich's newfound interest in disclosure and transparency, and his concern about an 'October surprise,' he should authorize the release of the complete record of the ethics proceedings against him," Romney spokeswoman Gail Gitcho said in a statement. 

Meanwhile, Santorum continues to portray himself as the party's true conservative and is trying to ride on the momentum of Thursday's surprise news that he led Romney by 34 votes in the final count of the leadoff Iowa caucuses. Romney initially had been declared the winner. 

"One candidate is too radioactive, a little too hot," Santorum told an audience Friday, referring to Gingrich. "There's too much about that candidate that we don't want to have" in a race that must focus on Obama's record, he said. "And we have another candidate who is just too darn cold, who doesn't have bold plans," Santorum said, alluding to Romney. 

Santorum added he's finally drawing enough campaign contributions to compete aggressively in Florida, the next primary state, and beyond, even if he finishes poorly in South Carolina. 

The Associated Press contributed to this report.