Concerns about the economy ran deep in South Carolina, where the unemployment rate is above the national average. An overwhelming 79 percent of voters said they were "very" worried about the direction of the economy.
The South Carolina Republican Party predicted a higher-than-normal turnout in today's primary. Turnout appeared to be mixed and varied throughout the state. It was, however, particularly heavy in Greenville, South Carolina's most populous county that has a history of favoring socially conservative candidates and voted in favor of Gingrich today. In 2008, Romney received only 17 percent of the votes in Greenville, a county that Mike Huckabee carried.
With Gingrich, Santorum and Romney all claiming a lead in one early state, analysts say the race is wide open.
The next Republican contest is in Florida, Jan. 31, where Romney has already poured millions of dollars on television advertising and on-the-ground efforts.
ABC News Emily Friedman, Gary Langer and Elizabeth Hartfield contributed to this report.