— They wanted a fighter.

On Saturday, as Newt Gingrich won a startling victory in the South Carolina Republican primary, many voters chose him for reasons that had little to do with his ideas, his hyper-complex proposals to fix immigration or Social Security.

Many voters said they liked the scrap in the former House speaker’s personality — his willingness to seek confrontations with his GOP rivals and the news media. That, they said, was what the GOP would need in the race against President Obama this fall.

“I think Mitt Romney is a good man,” said Harold Wade, 85, leaving a polling place in this picturesque seaside suburb outside Charleston. “But I think we’ve reached a point where we need someone who’s mean.”

And Gingrich, he said, was the only one mean enough.

“What we need is someone who’s got some brains,” Wade said, explaining his vote for the former speaker. “And we need someone with some guts.”

Surveys of voters at South Carolina polling places showed the roots of Gingrich’s resurgence. About two-thirds of voters said recent debates — in which Gingrich stood out, partly by blasting debate moderators for their questions — were the most important thing in their voting decision, or one of several important factors.

Equally important may have been what Romney, the former governor of Massachusetts, didn’t do this week. Weeks ago, back in Iowa, Romney’s campaign and supporters had crushed a Gingrich surge with ads that cast the former speaker as an unreliable conservative.

This time around, Romney’s supporters were slower to react. His campaign highlighted Gingrich’s 1997 reprimand for violating House ethics rules, and it rolled out legislators who said Gingrich had supported “earmarks” and pork-barrel spending.

But they may have waited too long.

Early last week, before those debates, polls showed Romney with about a 10-point lead in South Carolina. It seemed that this primary would be the beginning of a Romney cakewalk, and the beginning of Gingrich’s end.

Way back then, both Edmund Hardy and George McCutchen had sent in absentee ballots for Romney. On Saturday, they were still happy with that choice.

“I like Newt, and I would love to see him in a Cabinet position” said Hardy, 72. “He’s a bright guy.” But he thought the former speaker carried too much political baggage to win.

McCutchen, 67, said that one of the main reasons he voted for Romney was that he wanted to “speed this process up and have it come to a conclusion.”

“I hate what’s going on,” Hardy said. Both were still dressed in camouflage from a morning of duck hunting, digging into plates of pork at a barbecue restaurant called Sweatman’s in Holly Hills, S.C.

“The way they are beating each other up,” said McCutchen, “it opens wounds and unearths where the vulnerabilities are.”

Gingrich had done a good deal of that beating-up. He criticized Romney for not releasing his tax returns, arguing that “if there’s anything in there that is going to help us lose the election, we should know it before the nomination.”

And, for many in South Carolina, here was a signal of something important. Gingrich looked a man who was tough enough to win.

“We want someone who could beat Obama, and I think that’s Newt. He can handle him. Looking at Newt in the debates, he can handle anybody,” said Debbie Peterson of Piedmont. “I have a little bit of a problem with the divorces, but I need somebody to beat Obama. I like Romney, he is decent and moral, but I just don’t see him beating Obama.

“So it’s got to be Newt,” she said.

In Sullivan’s Island, E.P. Chiola had been for a third candidate — former senator Rick Santorum (Pa.). But then he thought about the battle ahead.

And he, too, turned to Gingrich.

“The more I thought about it, the more I decided I’m looking for a good fight,” Chiola said.

Romney, by contrast, spent the week fumbling to answer questions about his wealth and his tax returns. Some voters paid no mind to Romney’s troubles: Michael and Elizabeth Ricciardone of Mount Pleasant, S.C., said they still liked Romney’s business know-how and his steady character. They both voted for Romney on Saturday.

“It’s okay to be successful in this country. Redistribution of wealth is not in my vocabulary,” he said.

But others felt turned off.

“He’s too slick for me. Too polished,” said Jim Near, 56, a real estate agent and meteorologist from Mount Pleasant. “We all pay taxes. There should be no issue there. His responses were no good.”

He decided that Gingrich wouldn’t work, either: he had too much political baggage and that Santorum lacked the support to take the nomination. So, if Near couldn’t pick a candidate who would win, he would pick at least pick one he thought was leveling with him.

“Ron Paul seems the most honest. He’s not trying to portray himself as anything other than who he is,” Near said.

Staff writers Karen Tumulty, Philip Rucker, Nia-Malika Henderson and Jason Horowitz, all in South Carolina, contributed to this report.