The New York Times sums up the ugly nicely:
"Newt Gingrich won the primary by a decisive margin of more than 13 percentage points, and there is no mystery about how he did it. Two-thirds of voters interviewed in exit polls said they made their decision on the basis of the two South Carolina debates, where Mr. Gingrich exploited racial resentment and hatred of the news media to connect with furious voters.
"Mr. Romney’s foam-rubber ideology was not built for an electorate this rigid. Mr. Santorum’s profound social conservatism might normally have played well, particularly because two-thirds of primary voters said they were evangelical or born-again Christians, but he appealed only to Republican minds, not hearts.
"It was Mr. Gingrich who pulled the race into the gutter, where he found considerable support. He repeatedly called Mr. Obama 'the greatest food-stamp president in American history,' and lectured a black questioner at Monday’s debate about the amount of federal handouts to blacks, suggesting their work ethic was questionable."
Newt "The Swinger" has a national unfavorability rating of nearly 60%. That doesn't win elections, except in the angry, mouth-breather precincts of South Carolina, where race-baiting and media-bashing make the yahoos forget what a deeply unpopular shitsack they're voting for.