The former house speaker, Newt Gingrich's win in South Carolina marks a stunning change in direction in just one week.
According to exit polls, most voters said they made their minds up in the last few days of the campaign and two-thirds of them said the debates were an important factor in their vote.
Dramatic performances in the Myrtle Beach debate Monday night and in Charleston Thursday helped Gingrich surge from a double-digit deficit behind Mitt Romney to a 13 percent win in less than a week.
Evangelical Christians supported Gingrich, as did the Tea Party supporters and those who said the economy was the most important issue.
But the exit polls also showed that one important quality republican voters were looking for in a candidate was the ability to defeat president Obama this fall.
Gingrich had a slight edge among those voters, and Saturday night, in addressing his supporters in Columbia, Gingrich reserved his sharpest words for Obama, calling him the best food stamp president in history.
"If you want your children to have a life of dependency and food stamps, you have a candidate, it's Barack Obama. if you want your children to have a life of independency and paychecks, you have a candidate, that's Newt Gingrich and i'll bet you we have votes everywhere," said Gingrich.
Perhaps due to his success in the debates this week, Gingrich said if he is the republican nominee, he would challenge Obama to seven three-hour debates.