Romney, Paul lead in Iowa, but Santorum surging DES MOINES -- Mitt Romney and Ron Paul are in a statistical tie atop the field among likely Republican caucus-goers in Iowa, according to a new poll from the Des Moines Register. But the survey shows a surge for Rick Santorum, who topped Paul on the final two days of polling. Romney secured 24 percent support in the survey, conducted Tuesday through Friday, with Paul coming in at 22 percent -- within the poll's four point margin of error. Santorum followed with 15 percent. Newt Gingrich came next with 12 percent support, followed by Rick Perry with 11 percent and Michele Bachmann with 7 percent. In polling over Thursday and Friday, Santorum came in with 21 percent support, while Romney held steady with 24 percent. Paul came in third over these last two days with 18 percent support. The findings prompted Register pollster J. Ann Selzer to say in a story released by the newspaper, "Momentum's name is Rick Santorum." The survey found that four in 10 likely Republican caucus-goers say they are willing to change their mind before the Jan. 3 caucuses, which kick off the primary season. Gingrich led with 25 percent support in the previous Register poll, in November, but has fallen 13 points since then. Santorum, one of the few GOP candidates to have not seen a surge before now, has been crisscrossing Iowa in hopes that a strong caucus finish could give a boost to his longshot campaign. A strong social conservative, he has been engaged in a fierce competition for the support of the state's evangelical and born again voters, most directly with Bachmann and Perry. Rick Santorum tries to make his moment last Full CBSNews.com coverage: Election 2012