In January 1997, Gingrich became the first speaker ever reprimanded and fined for ethics violations, slapped with a $300,000 penalty. He said he'd failed to follow legal advice concerning the use of tax-exempt contributions to advance potentially partisan goals, but he was also cleared of numerous other allegations.
At the same time he fended off a demand on one front Friday, Gingrich was less than eager to face further questions made by his second wife, Marianne, who said in an ABC interview broadcast Thursday night that he had once sought an open marriage so he could keep the mistress who later became his current wife.
He denies the ex-wife's account.
On his final lap through the state, Santorum campaigned as the Goldilocks candidate — just right for the state's conservative voters.
"One candidate is too radioactive, a little too hot," he said, referring to Gingrich. "And we have another candidate who is just too darn cold, who doesn't have bold plans," he added, speaking of Romney.
His campaign also announced endorsements from conservative leaders in the upcounty portion of the state around Greenville, where the heaviest concentration of evangelical voters lives.
Santorum, a former Pennsylvania senator, dismissed Texas Rep. Ron Paul, the fourth contender in the race. "There are four, three of whom have a chance to win the nomination," he said, including himself.
Paul, who finished third in the Iowa caucuses and second in the New Hampshire primary, has had a limited presence in South Carolina.
But he flew to six cities on a burst of campaigning on the race's final day, and drew applause for having returned to Washington, D.C., earlier in the week to vote against Obama's requested increase in the debt limit.
"When you hear the word principle, you think of Ron Paul. He's the embodiment of that," said Derek Smith, a 26-year-old engineer for the Navy in Charleston. "If he were to run as a third-party candidate, I would vote for him unconditionally."
Paul has said he has no intention of doing that.
Interviewed on C-SPAN, Santorum said the race "has just transformed itself in the last 24 hours." It was hard for any of the campaigns to argue with that.
In a bewildering series of events on Thursday, Romney was stripped of his victory in the Jan. 3 Iowa caucuses by state party officials, who said a recount showed Santorum ahead by 34 votes.
Then came an unexpected withdrawal by Texas Gov. Rick Perry, who endorsed Gingrich. But Gingrich was suddenly caught in a controversy caused by his ex-wife's accusations.
At a two-hour debate that capped the day, Gingrich drew applause when he strongly attacked ABC and the "liberal news media" in general for injecting the issue into the final days of the South Carolina campaign.
By contrast, Romney faced a round of boos from the audience when he stuck by earlier statements that he would wait until April to release his tax returns.
Romney has stumbled several times in recent days, including once when he said he paid an effective tax rate of about 15 percent. That's half what many middle-income Americans pay, but it's what the law stipulates because his income derives from investments, which are taxed at a lower rate than wages.
Gingrich posted his own tax returns online during the Thursday debate, reporting he paid 31.5 percent of his income to the IRS.
Associated Press writers Charles Babington, Kasie Hunt, Thomas Beaumont, Philip Elliott, Beth Fouhy and Shannon McCaffrey contributed to this report.
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