COLUMBIA, S.C. (AP) -- Newt Gingrich stormed to an upset win in the South Carolina primary Saturday night, dealing a sharp setback to Mitt Romney and scrambling the race for the Republican presidential nomination.
"Thank you, South Carolina!" Gingrich swiftly tweeted to his supporters. He appealed for a flood or donations for the next-up Jan. 31 primary. "Help me deliver the knockout punch in Florida. Join our Moneybomb and donate now," he tweeted.
Already, Romney and a group that supports him were on the air in Florida with a significant ad campaign, more than $7 million combined to date. Romney had hoped that Florida would seal his nomination - if South Carolina didn't first - but that strategy disappeared Saturday night.
Former Pennsylvania Sen. Rick Santorum and Texas Rep. Ron Paul trailed badly in the South Carolina voting.
Exit polling showed Gingrich, the former House speaker, leading by a wide margin among the state's heavy population of conservatives, tea party supporters and born-again Christians.
For the first time all year, Romney trailed among voters who said they cared most about picking a candidate who could defeat President Barack Obama this fall. Gingrich was ahead of the field for those voters' support.
There were 25 Republican National Convention delegates at stake, but political momentum was the real prize with the race to pick an opponent to President Barack Obama still in its early stages.
In all, more than $12 million was spent on television ads by the candidates and their allies in South Carolina, much of it on attacks designed to degrade the support of rivals.
Interviews with voters as they left polling places showed nearly half saying their top priority was finding a candidate who could defeat Obama in the fall, followed by wishes for experience, strong moral character and true conservatism.


