A new Reuters/Ipsos poll has Romney up by 21 in South Carolina:
The poll showed 37 percent of South Carolina Republican voters back Romney. Congressman Ron Paul and former Senator Rick Santorum tied for second place with 16 percent support.
Gingrich, a former speaker of the House of Representatives, has fallen far back after holding a strong lead in South Carolina in December. He was in fourth place at 12 percent in the Reuters/Ipsos poll.
"In primary races things can change quickly but it does look like Romney is in position to win South Carolina, and if he wins ... that's sort of the end of the road for most of his challengers," Ipsos pollster Chris Jackson said.