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Entrance poll results indicate that Mormons account for about a quarter of caucus participants in Nevada today, about the same as their share in 2008 and far more than in previous contests this year - a natural affinity group for Mitt Romney. Evangelical Christians, by contrast, are far less numerous than they were in most previous GOP 2012 events.

The entrance poll, analyzed for ABC by Langer Research Associates, shows Romney won 95 percent of Mormons in the 2008 caucuses. But he also won broadly in other faith groups in Nevada four years ago, including by 17 points among evangelicals, a group in which he's struggled elsewhere. Entrance poll results indicate that evangelicals account for about a quarter of caucus participants in Nevada today, compared with 65, 57, and 47 percent, respectively, in South Carolina, Iowa and Florida. (They were less numerous in New Hampshire.)

Nevada, at the same time, is rich in "very" conservative voters, accounting for nearly half of caucus-goers. That's about the same as in Iowa, and substantially more than in New Hampshire, South Carolina or Florida alike. Again, though, while Romney has struggled among very conservative voters this year, losing them in all but New Hampshire, he won very conservatives by a vast margin in Nevada in 2008, on his way to a romp there. Romney won the caucuses four years ago with 51 percent of the vote, nearly 40 points ahead of his closest competitors.

Ron Paul, who pushed to do well in Nevada this year, may suffer from a deficit of self-identified independent voters, a group in which he's tended to do better. They account for just about two in 10 caucus-goers in Nevada today, better than their share in 2008, but still heavily outnumbered by mainline Republicans. Paul's also done well among young voters; today the entrance poll indicates that they make up barely one in 10 caucus-goers.

On candidate attributes, as elsewhere, Nevada caucus-goers are focused on the candidate who's best able to defeat Barack Obama - more than four in 10 say it's the top item in their vote, more than double the number who chose any other option (moral character, "true conservative," having the right experience). On issues, the economy again dominates.