Mitt Romney snapped back from South Carolina with a Florida primary victory that took advantage of a more diverse electorate, re-established his image of electability and economic leadership, and demonstrated his organizational firepower in attracting - and retaining - early-deciding voters.

Far fewer Florida voters made up their minds in the campaign's closing days than in any previous GOP contest this year - and Romney won his largest share of those who did. His final barrage of ads may have helped limit the number of late-deciding voters and stemmed defections in this group.

Romney had other advantages - much more positive personal appeal than his top competitors'; a sharp gender gap for the first time this year, with far greater support among women; fewer evangelicals, a group with which he's struggled; lots of seniors; and, in another first for the GOP in 2012, a substantial number of minority voters, primarily Hispanics.

Yet while the result pulled Romney back to his strong New Hampshire showing, there was enough in the results to give Newt Gingrich a continued line of attack. A substantial 41 percent of Florida voters described Romney's positions on the issues as "not conservative enough." Gingrich, indeed, won "very" conservative voters by a broad 43 to 29 percent, won the strongest anti-abortion voters by 13 points and won strong supporters of the Tea Party political movement - more than a third of all Florida primary voters - again by 13 points.

In a more general kvetch (and possible nod to ex-Gov. Jeb Bush), nearly four in 10 voters said they'd like to see someone else run for the nomination. But Romney nonetheless prevailed on enough personal measures to stick it to Gingrich - and to overcome negative-campaigning criticism at the same time. Sixty-five percent of Florida voters said they'd be satisfied with Romney as the Republican nominee - well more than said the same about Gingrich or Rick Santorum, 53 percent apiece. And more, a broad 76 percent, expressed a favorable opinion of Romney overall - compared with 55 percent for Gingrich.

Gingrich also may have trouble sustaining another argument, the claim he'd have run a closer race without Santorum in the contest. To the contrary, Santorum's voters were more apt to see Romney favorably than Gingrich, 63 percent vs. 49 percent, and equally apt to say they'd be satisfied with either of them as the eventual Republican nominee.

Further, while Gingrich tried to paint Romney as out of touch with average Americans, Romney led him, albeit slightly, on this score - 34 percent said Romney best understands the problems of average Americans, vs. 27 percent for Gingrich. Notably, that leaves 32 percent who picked Santorum or Paul (19 and 13 percent, respectively) on this attribute, making it a weak spot for Romney and Gingrich alike.

Elsewhere, though, Romney shone. Forty-five percent of voters selected defeating Barack Obama as the most important candidate quality, matching the high in South Carolina. Among those who gave it the top slot, moreover, 58 percent voted for Romney, rivaling his New Hampshire showing among beat-Obama voters, and 25 points ahead of Gingrich.

The advantage on electability more than negated Gingrich's strong lead among voters most focused on a "true conservative," since there were far fewer of them, just 14 percent. Gingrich's lead over Romney among voters mainly focused on experience was in the single digits. And among the 17 percent looking chiefly for the candidate with "strong moral character," Romney crushed Gingrich, 45 percent to 8.

For the first time this year there was a striking gender gap in the results; men favored Romney by just 5 points, 41-36 percent, over the thrice-married Gingrich, while women supported Romney by more than 20 points, 51-29 percent.

Another notable result was the number of early deciders in this contest. Four in 10 came to their decision in December or earlier, before any of the barrage of campaign ads hit the airwaves. And those early deciders favored Romney over Gingrich by 2 to 1, 54-27 percent.

On the flipside, only 28 percent decided in Florida in the last few days - about half the number of late deciders as in South Carolina, 55 percent. Romney won these late deciders, but by a much narrower margin, 42-34 percent.

The volley of campaign advertisements - predominantly by Romney, and generally characterized as negative - seems to have helped him. Romney won voters who said the campaign ads didn't matter to them, but just by 7 points. His margin grew among the four in 10 who said the ads did matter, to a vast 57-27 percent.

Romney also did better with late deciders than in any other state, and there were fewer of them, suggesting the ads may have kept early voters at his side. And there was no apparent negative effect.

Asked who ran the "most unfair campaign," voters divided about evenly between Romney and Gingrich.

Among other notable results:

Evangelicals accounted for 46 percent of voters, up from their share in 2008 but still far below their 65 percent in South Carolina. And, as in New Hampshire, Romney did better with them: He split evangelicals about evenly with Gingrich, after losing them by 2-1 in South Carolina. Among non-evangelicals, moreover, Romney won in Florida by 54-26 percent.

In another example of a more diverse electorate, more than three in 10 Florida voters were Catholics, compared with 13 percent in South Carolina. Romney won them by 26 points. In another, after contests in which 98 or 99 percent of voters were white, that proportion eased to 83 percent in Florida. Romney won whites by 11 points - and won nonwhites, mainly Hispanics, by twice that margin, 23 points.

Seniors accounted for nearly four in 10 Florida GOP primary voters, well above the younger electorate in South Carolina, where only 27 percent were seniors. They've been a consistently better group for Romney, and while he prevailed among all groups, his support barely cracked 50 percent among seniors, a feat in a four-candidate race.

Romney also again did particularly well among better-off voters, winning those with $100,000-$200,000 incomes by 15 points, and the few with more than $200,000 incomes by a vast 61-23 percent, his highest support in any demographic group. At the same time, Romney also won voters with less than $50,000 incomes, albeit by a closer 42-32 percent.

More than six in 10 voters said the economy was the most important issue, No.1 by far, as in previous contests. And among those who picked it, Romney beat Gingrich by 51-31 percent. After losing them to Gingrich in South Carolina, that's Romney's best showing to date among economy voters - better even than in New Hampshire.