NBC News: Romney dominates Nev. caucus

LAS VEGAS - (AP) -- Preliminary results of a poll of voters in Nevada's Republican presidential caucuses show Mitt Romney's victory flowing from his best performance yet among conservatives plus overwhelming backing from the state's Mormons.

The former Massachusetts governor's support was broad as well as deep. He was the clear winner among all but the lowest-earning voters and every age group but those under 30.

One in 4 voters was Mormon, as is Romney, and 9 in 10 backed him. Romney also carried Catholics and Protestants.

Around 4 in 5 called themselves conservative, tying Nevada with Iowa as the most conservative group of voters yet in this year's five GOP presidential contests. Nearly 6 in 10 of them supported Romney. Until now, he'd won no more than 4 in 10 conservative votes.