The first "entrance" polls are in from the Iowa caucuses, and they show that among the top tier of candidates, Mitt Romney is viewed as the most electable, Ron Paul is winning independents, and Rick Santorum is a favorite among voters who say they're very conservative.

ABC News' Gary Langer, of Langer Research Associates, reports that Romney trails Paul and Santorum among evangelical Christians, according to the polls taken of voters as they began the caucuses (they can change their minds throughout the process). Paul and Santorum split that Christian vote, the polls indicate.

"Romney is making back ground among non-evangelicals, and among those looking mainly for the candidate they think is best able to beat Barack Obama," Langer writes. "Since beating Obama is the leading candidate attribute - a third say it's the most important trait - this keeps Romney in the hunt."

Paul, who has relied on his steady base of support, is winning the majority of those attending their first caucus - and that's 40 percent of the voters there, according to the entrance surveys. Independents were also "tilting heavily" toward him, and young people picked him, too, as of the beginning of the night.

Romney and Santorum, meanwhile, do better among caucusers who made their choice in the last few days, the polls show.

"Very conservatives - nearly half of caucus goers - are a better group for Santorum, with Paul and Romney trailing him in this group," Langer adds. "Attributes make for sharp divisions: Big lead for Romney, as noted, among those who cite defeating Obama as the most important attribute, also among those looking mainly for experience in a candidate. Those looking chiefly for a 'true conservative' go for Paul by a very wide margin; for the candidate with 'strong moral character,' better for Santorum, then Paul, both well ahead of others."