Matt Rourke / AP Photo

A smashing result among voters who focused on the pre-primary debates lifted Newt Gingrich to victory in South Carolina, breathing new life into his candidacy - and dealing a stern blow to Mitt Romney, who struggled especially with the state's evangelical and strongly conservative voters.

Exit poll results found that nearly two-thirds of Republican primary voters called the debates important to their vote, and they favored Gingrich over Romney by a vast 50-22 percent. More than half of voters also decided in just the last few days - more than in either Iowa or New Hampshire - and they likewise went overwhelmingly for Gingrich, by a 22-point margin over Romney, 44-22 percent.

Gingrich's persuasiveness in the debates helped push him to an advantage even in electability, previously Romney's strong suit. Forty-five percent of South Carolina voters were focused chiefly on the candidate who's best able to defeat Barack Obama in November - and these voters favored Gingrich over Romney by a 14-point margin, 51-37 percent.

The exit poll, analyzed for ABC by Langer Research Associates, found that other groups in which Romney has struggled, particularly in Iowa, went heavily to Gingrich. He won very conservative voters - more than a third of the electorate - with 47 percent of their votes. Rick Santorum and Romney trailed in this group, with 24 and 19 percent, respectively. And Gingrich won 44 percent of evangelicals, who accounted for 65 percent of GOP primary voters in the state, again beating Romney and Santorum alike by more than 2-1 margins.

Another result reflected the strong element of religious preference in this primary: Six in 10 voters said it mattered to them that a candidate shares their religious beliefs, and again this group went to Gingrich over Romney by more than 2-1, 46-19 percent (an additional two in 10 backed Santorum). Indeed among the quarter of voters who said shared religious belief matters "a great deal," Romney cratered to last place, with just 9 percent support.

Among those who called shared religious beliefs less important, by contrast, Romney finished ahead of Gingrich, by 7 points.

The controversy over Romney's experience at Bain Capital may have done him some damage as well. While almost two-thirds saw his work there positively, a not-insubstantial 28 percent saw it as a negative - and among these voters Romney had essentially no support - 3 percent, to Gingrich's 50. Skeptics of his experience at Bain disproportionately included lower-income voters, as well as those focused on moral character.

Gingrich also scored strongly among the remarkable 79 percent of South Carolina voters who said they were "very worried" about the nation's economy. Romney won this group easily in New Hampshire, with 41 percent of the vote. In South Carolina that plummeted to 27 percent, with 41 percent for Gingrich.

Comments by one of Gingrich's ex-wives that he was unfit for office appeared not to resonate strongly. Gingrich won women by 38-29 percent over Romney - a narrower margin than among men, 42-26 percent, but a convincing victory nonetheless. Among married women, Gingrich had 41 percent support; among evangelical women, 42.

There was some effect: The second-most cited candidate attribute among women, after electability, was "strong moral character," and exceedingly few of the women focused on this quality, 6 percent, voted for Gingrich. But he more than made it back among the majority of women who picked other attributes as greater concerns.

The results reflected a greater coalescing of non-Romney voters - to Gingrich's advantage - than seen in the two previous contests. Many of the groups that previously divided among Santorum and Ron Paul lined up more conclusively in South Carolina behind Gingrich, who represented Congress from a district in next-door Georgia.

Romney may look to a variety of misplays. His hesitating position on release of his tax returns may have played a role in damaging his image of electability. It also may have hurt views of his leadership more broadly, and economic leadership by extension; among the broad majority of voters who cited the economy as the most important issue, Gingrich beat Romney by 40-32 percent - narrower than Gingrich's margin overall, but a win in a group that Romney owned in New Hampshire and Iowa alike.

Romney also may have suffered from the criticism he took from Santorum on abortion (with no apparent benefit to Santorum himself). Voters who want abortion illegal in all or most cases - 64 percent of the electorate - favored Gingrich, with 45 percent of their vote, to Santorum's 22 percent, Romney's 21.

Romney improved from his 15 percent in South Carolina four years ago - but not among all groups. He did 25 points better than in 2008 among moderates, 23 points better among $200,000-plus voters and 21 points better among those with a postgraduate education. He also gained 10 points among evangelicals - but just to 21 percent. And he did no better now vs. 2008 among very conservative voters, or among those most focused on shared religious beliefs.

Some salve for Romney came from a result in which 86 percent of South Carolina Republican voters said they'd line up behind him if he ultimately were the party's nominee. But far fewer, just 38 percent, said they'd do so enthusiastically. And suddenly Romney's looking at a longer, tougher road to get there.

The challenge increased for others as well. Santorum, newly certified as the first-place finisher in the Iowa caucuses by a 34-vote margin, came off a nothing-doing result in New Hampshire with a rather distant third in South Carolina. And Paul, second behind Romney in New Hampshire, came in fourth in South Carolina, with little in the way of standout results. He finished numerically ahead of Gingrich among young voters, but they were far too few in number to tilt the table. (And Paul competed with Romney for second place among independents - but Gingrich won them.)

Older voters showed up in large numbers; senior citizens accounted for 27 percent of the turnout - and they were another group in which Gingrich took it to Romney, beating him 47-36 percent. Romney had won seniors handily in Iowa and New Hampshire alike.

Romney held the fort in another group, winning voters with household incomes over $200,000 by a 16-point margin over Gingrich. But they made up just one in 20 voters, and he did far less well among those less well-off financially, particularly the broad majority, 73 percent, with incomes under $100,000. Gingrich won 40 percent in that group, Romney, 24 percent.

Again, though, some of Romney's greatest struggles were in some of the base Republican groups - evangelicals, strong conservatives, strong supporters of the Tea Party movement - in which he's been challenged throughout the season. He narrowly won moderates in South Carolina, 36-31 percent over Gingrich. But "somewhat" conservatives went 41-30 percent for Gingrich, and among very conservatives, as noted, the contest turned into a 28-point rout. Among strong supporters of the Tea Party movement, likewise, Gingrich won by more than 2-1.

The fractured outcome of the Republican races to date - in particular, the striking turnaround for Gingrich, who won just 13 percent support in Iowa and 9 percent in New Hampshire - turns a bright light on their next stop, Florida, a state with what may be yet another markedly different mix of Republican voters.

Evangelicals accounted for just 39 percent of the Florida GOP electorate in 2008, vs. their 65 percent in South Carolina this Saturday. Very conservative voters made up 27 percent in Florida in '08, vs. their 36 percent in South Carolina this year. Florida has fewer low-income voters, fewer independents (it's a closed primary) and more seniors. It also has some racial diversity: Sixteen percent of GOP primary voters there in 2008 were non-white. Whites, by contrast, have accounted for 99 percent of primary voters in Iowa, New Hampshire and South Carolina.

There also are wildcards aplenty. One is the highly changeable nature of the Republican primary electorate this year, and its late-stage final decision-making. Another: The fact that, between now and their Florida contest, the candidates have agreed to two more debates.

By Gary Langer, with Patrick Moynihan, Julie Phelan, Gregory Holyk and Damla Ergun.