Newt Gingrich posted a double-digit victory in Saturday’s South Carolina primary, with late deciders delivering a clear rebuke to Mitt Romney, the one-time-front-runner.

In the exit poll of voters as they left polling places in South Carolina Tuesday, nearly two-thirds said recent debates were an important factor in their vote, and Gingrich won them by a resounding 50 to 22 percent margin over Romney. You can see the full exit poll results using the Post’s Primary Tracker, where you can sort each candidate by their best and worst groups.

Here are the top exit poll findings:

Late deciders - Gingrich’s debate performances in the past week may have won over late-deciding voters. In the exit poll, more than half of voters said they decided in the closing days of the campaign, and Gingrich won by 20 points in this group. Romney tied Gingrich among those who decided earlier.

Beating Obama - Unlike in Iowa and New Hampshire, Gingrich beat Romney among those who prioritized an ability to win in November over other candidate qualities. Some 45 percent said this was the most important trait in a candidate, a bigger hunk of the electorate than in Iowa or New Hampshire. Romney won “electability” voters in the two previous contests by overwhelming margins (63 to Gingrich’s 11 percent in New Hampshire, and 48 to 20 percent in Iowa). In South Carolina, Gingrich won a slim majority of these voters.

Dissatisfaction with Romney - Exit polls show fewer than four in 10 primary voters saying they would enthusiastically support Romney if he were the party’s nominee. Nearly half would back him, but with reservations. About one in 10 said they wouldn’t back him at all. Gingrich cleaned up among voters with reservations about Romney, winning 50 percent of their votes. A large proportion of Paul’s supporters said they wouldn’t back Romney in November if he ended up as the GOP standard-bearer.

Religious right - Though fewer say candidates’ religious beliefs were a factor in their vote than in 2008, Gingrich led by a wide margin among these voters in exit poll data. He also won by a wide margin among evangelical Christians, who made up a big majority of the electorate. Romney about doubled his share of the evangelical vote from 2008, but as in Iowa he is much stronger among non-evangelical voters. In all, nearly three-quarters of Gingrich’s support in South Carolina came from evangelicals; just over half of Romney’s did.

Little gender gap on Gingrich - Despite recent allegations that Gingrich offered his ex-wife an “open marriage,” exit polls show he got nearly as much support from women as men in South Carolina. He did beat other candidates by a somewhat larger margin among men, but was tops among women as well, including among married women (41 to 28 percent over Romney).

Strong tea party supporters - They’ve been loyal to Gingrich in national polling and came out strong for him Tuesday. About one in three voters were “strong” tea party supporters, and he more than doubled Romney’s support among this group.

Romney’s moderate mix - Romney outperformed others among tea party opponents, those who said they want to keep abortion legal and moderate to liberal voters. These are all relatively small voting groups in South Carolina, and Romney lost to Gingrich by big margins among conservatives, tea party backers and anti-abortion voters.

Older voters - Gingrich neutralized Romney’s advantage among older voters in South Carolina, beating him among those age 45 and up. Romney’s support peaked among older voters in Iowa and New Hampshire, and the latest Washington Post-ABC News national poll found Romney leading Gingrich by more than 2 to 1 among Republicans and GOP-leaning independents age 45 and older.

Bain - For all the negative attention on Romney’s private equity work for Bain Capital, nearly two-thirds of voters in exit polls said they have a positive view of Romney’s business background, while just under three in 10 had negative views. Among those who hold positive views, Romney edged out Gingrich by only four points, but Romney won almost no voters who saw his private sector work negatively.

Santorum’s values voters not enough - Rick Santorum owes his narrow finish ahead of Paul to values voters. The exit poll shows he won big among voters prioritizing abortion as the top voting issue and those looking for a candidate with strong moral character. But too few voters in the state were focused on these items for Santorum to break through to a higher finish.

Paul settles for fourth place - Paul’s best groups were also relatively narrow slices of the electorate: younger and independent voters. Paul won about one in three voters under age 30 and about a quarter of independents. Paul also did well among those looking for a “true conservative” but placed behind Gingrich and Santorum on this count. Paul’s very best group were the slender piece of the electorate who said they would not support Romney if he were the nominee, perhaps opening the door a crack for a third party run.

These are results from Republican primary poll of 2,381 voters as they exited primary voting places in South Carolina on Jan. 21, 2012. The poll was conducted by Edison Media Research for the National Election Pool, The Washington Post and other media organizations. Typical characteristics have a margin of sampling error of plus or minus three percentage points.

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