(CNN) - A large gender gap appears to be developing between supporters of GOP presidential candidates Mitt Romney and Rick Santorum, as well as a split between white collar and blue collar Republicans, according to a new national survey.
A CNN/ORC International poll also indicates that Santorum supporters are much more highly motivated than those backing Romney.
"The new numbers indicate a split in the Republican party that goes deeper than ideology, with signs of a gender gap and class warfare breaking out in the GOP ranks," says CNN Polling Director Keating Holland.
According to the survey, released Tuesday afternoon, Santorum and Romney are basically all tied up for the lead in the race for the GOP nomination. Thirty four percent of Republicans and independents who lean towards the GOP say they back Santorum, the former senator from Pennsylvania, with 32% backing Romney, the former Massachusetts governor who has been at or near the top of national polling over the past year. Santorum's two point margin over Romney is well within the survey's sampling error.
The poll indicates that Rep. Ron Paul of Texas is at 16%, with former House Speaker Newt Gingrich at 15%. Four other surveys released over the past day also suggest the race for the nomination knotted up between Romney and Santorum. All of the polls, including the CNN survey, were conducted entirely after Santorum's victories over Romney, Gingrich and Paul last Tuesday in caucuses in Colorado and Minnesota and a non-binding primary in Missouri. Santorum's sweep of the February 7 contests sparked his surge in national and state polling, and cemented the perception that Romney was having a hard time locking down support of core conservatives.
Santorum's newfound support may be coming from Republicans who backed candidates who are no longer in the race, like Texas Gov. Rick Perry. But the poll also indicates that Santorum's surge is also the product of a notable gender gap, with Santorum holding a 10-point edge among Republican men and Romney winning Republican women by nine points. And Republicans who describe themselves as blue collar are backing Santorum by 11 points over Romney. But among those who say they come from white collar families, Romney has a 10-point advantage.
The poll also indicates Santorum topping Romney 45% to 29% among self-described tea party movement supporters, with Romney edging out Santorum 34% to 29% among people who don't describe themselves as tea party supporters.
It's a similar story when it comes to self described born-again voters, with Santorum leading that group by a 42% to 24% margin over Romney, and Romney beating Santorum 40% to 26% who don't describe themselves as born-again.
"According to the survey, Santorum Republicans are also much more highly motivated than Romney Republicans, with more than half of Santorum's voters saying they strongly support him, compared to less than four in ten Romney voters - and enthusiasm for Santorum as the eventual nominee is highest among the four remaining challengers," adds Holland.
Nonetheless, an overwhelming number of Republicans see Romney as most likely to win the GOP nomination, and a majority continues to believe that Romney has the best chance of defeating President Barack Obama in the November general election.
Are Republicans happy with the remaining choices in the field? The poll indicates the answer is yes, but satisfaction with current candidates has slipped 11 points since the fall. And the eventual winner may receive a less-than-enthusiastic response from the GOP rank and file. Only a third say they would be enthusiastic about a Santorum victory, and that puts him at the top of the field. Only one in five say they would be enthusiastic if Romney were the nominee.
The CNN poll was conducted by ORC International from February 10-13, with 478 Republicans and independents who lean towards the GOP questioned by telephone. The survey's overall sampling error is plus or minus 4.5 percentage points.