COLUMBIA, S.C. — For months, the big question in the GOP presidential race was whether Mitt Romney would falter if one rival could consolidate the anti-Romney feelings of many hard-core conservatives.

The answer seemed a step closer Thursday in South Carolina, when Texas Gov. Rick Perry quit the race and endorsed Newt Gingrich, who already was thought to be rising. Also helping Gingrich are Rick Santorum’s apparent troubles here, partly fueled by harsh TV attack ads aired by yet another candidate, Ron Paul.

But the political fates were equally cruel and kind Thursday, leaving Saturday’s primary in as much doubt as ever.

Just when Gingrich, the former House speaker, was accepting Perry’s nod, ABC News aired portions of an interview with his second wife, Marianne. She said Gingrich had asked for “an open marriage” so he could continue his affair with a House staffer, now his third wife, Callista.

The comments aren’t likely to go down well with South Carolina’s evangelical voters, who made up 60 percent of the GOP electorate here four years ago.

Santorum, the former senator from Pennsylvania, has been trying to woo those voters. Even with last week’s embrace by a national group of social conservative leaders, however, he has shown modest progress, on the surface, at least.

Meanwhile, just when Romney seemed poised to coast into Saturday’s election with a badly fractured opposition, he got two doses of bad news along with Perry’s endorsement of Gingrich.

One was minor: It’s possible that the former Massachusetts governor narrowly lost the Jan. 3 Iowa caucus to Santorum rather than having won it by eight votes. The true outcome may never be known.

More damaging for Romney, his campaign acknowledged that some of his enormous personal wealth is invested in the Cayman Islands, a popular tax shelter. Aides said Romney didn’t use the islands for that purpose. But the admission is certain to raise more questions about a touchy subject for Romney: his personal fortune and frequent tone-deafness on money matters.

He has acknowledged that he pays an effective tax rate of about 15 percent, lower than what he would pay if he earned a regular paycheck like many Americans. He once challenged Perry to a $10,000 bet over a disputed detail during a televised debate. And Romney has said he earned “not very much” by making speeches, although the total was $373,327 over 12 months.

Romney has grudgingly said he will release his tax returns in April. The Cayman hubbub will add to the pressure.

A number of veteran GOP campaign strategists say the campaign’s increased confusion and disarray doesn’t change Romney’s front-runner status, even if he might need more time, and more states, than he had hoped to lock up the nomination.

“All of this really just still points to a Romney nomination,” said longtime Republican adviser Terry Holt. South Carolina will be close, he said. But in the long run, “Newt is unelectable,” Holt said.

Gingrich’s fans will argue with that. But other unaligned GOP strategists agree Romney still has the edge.

“I still think it’s advantage Romney, given that Santorum and Gingrich will split some votes and Romney can take the rest,” said Brian Nick, who has lived in South Carolina and is monitoring the race from nearby Charlotte, N.C. Looking beyond South Carolina, he said, “the path to victory definitely favors Romney in places like Florida, Nevada and Michigan.”

Florida, which votes Jan. 31, is a big, expensive state. Romney’s superior money and organization might overwhelm anything that Gingrich or Santorum can bring to bear. Paul, the Texas congressman, rarely crops up in such conversations, because his loyal, libertarian-leaning fans are essentially a separate and limited constituency that’s not up for grabs.

Nevada has many Mormons, a boon for Romney, who is Mormon. And his father, George Romney, was governor of Michigan.

If Gingrich is closing the gap on Romney in South Carolina, as some think, then small intangibles might make a difference. Rain is forecast for Saturday, and Romney’s heftier get-out-the-vote operation could possibly give him a slight edge.

On the other hand, another debate was scheduled for Thursday night, in Charleston, and Gingrich has often seen bumps in his polls after such forums.

Gingrich apparently gained little traction earlier this month by attacking Romney’s record at Bain Capital, a private equity firm with a record of both adding and subtracting jobs in companies it reorganized. A pro-Gingrich super PAC has essentially stopped airing its TV attack ad based on Bain.

But Gingrich may have struck a nerve in last Monday’s debate when he said, “more people have been put on food stamps by Barack Obama than any president in American history.” He also vowed to “help poor people learn how to get a job.”

Some, including former President Jimmy Carter, said the comments were meant to strike racial chords among white conservative voters. Gingrich denied the charge, and put the debate clips in a TV ad running heavily on South Carolina stations.

It’s possible that Thursday’s dramas will have little impact on Saturday’s voting. Holly Gatling, a former news reporter and current anti-abortion activist in the state, said she believes most voters have already made up their minds.

“I’m not sure we’re going to see a big surge for anybody,” she said.

As for the highly negative ads on TV, and Gingrich’s ex-wife’s comments, Gatling said many voters might shrug them off as nothing new. “Politics are rough and tumble in this state,” she said.

By Sunday morning, the attack ads will be over, and the political and media circus will have moved on to Florida.

———

EDITOR’S NOTE — Charles Babington covers politics for The Associated Press in Washington.