LAS VEGAS — Republican presidential front-runner Mitt Romney cruised to victory in the Nevada caucuses Saturday night, notching a second straight triumph over a field of rivals suddenly struggling to keep pace.
In victory, the former Massachusetts governor unleashed a sharp attack on President Barack Obama, whose economic policies he said have "made these tough times last longer."
In a state with the worst joblessness in the country, Romney added, "This week he's been trying to take a bow for 8.3 percent unemployment. Not so fast, Mr. President. This is the 36th straight month with unemployment above the red line your own administration drew."
The former Massachusetts governor held a double-digit lead over his nearest rival as the totals mounted in a state where fellow Mormons accounted for roughly a quarter of all caucus-goers.
Former House Speaker Newt Gingrich and Texas Rep. Ron Paul vied for a distant second. Former Pennsylvania Sen. Rick Santorum trailed the field.
Returns from 14 of 17 counties showed Romney with 42 percent support, Gingrich with 25 percent, Paul with 20 percent and Santorum with 13 percent.
Yet to report its results was Clark County, which includes Las Vegas and often accounts for half or more of the votes in a statewide election.
In contrast with Florida's intense primary, Nevada caucuses were sedate — producing little television advertising and no candidate debates.
A total of 28 Republican National Convention delegates were at stake in Nevada. Romney won at least 10, Gingrich at least four, Paul at least three and Santorum at least two. Eight were still to be determined.
By contrast, Romney's victory on Tuesday netted him all 50 of Florida's delegates.
According to the AP count, Romney began the day with 87 of the 1,144 delegates needed to win the Republican nomination. Gingrich had 26, Santorum 14 and Paul 4.
Preliminary results of a poll of Nevada Republicans entering their caucuses showed that nearly half said the most important consideration in their decision was a candidate's ability to defeat Obama this fall, a finding in line with other states.
About one-quarter of those surveyed said they are Mormon, roughly the same as in 2008, when Romney won with more than a majority of the vote in a multi-candidate field.
Romney rode overwhelming backing from Mormons and his best performance yet among conservatives to his emphatic victory Saturday in Nevada's Republican presidential contest, according to preliminary results of a poll of voters entering the caucuses.
Buoyed by near monolithic support from Mormons, the former Massachusetts governor won a broad and deep victory. He was the clear winner among every age group except for those under 30, with all but the lowest-earning voters and across all levels of education.
Romney captured the votes of just over half of conservatives, more than doubling the number who backed former Gingrich, an ominous result for the man who has emerged as Romney's chief rival.
In the four previous states that have held GOP presidential contests, Romney won no more than about 4 in 10 conservative votes, in New Hampshire and Florida. Underscoring the importance of the Mormon vote, Romney's support Saturday among conservatives who are not Mormon was in that same 4 in 10 range.
For the first time, Romney took half the votes of tea party supporters, with Mormons once again pushing his margin higher than before.
One in 4 voters Saturday was Mormon, Romney's religion, and 9 in 10 of them backed him. They gave him more than 4 in 10 of his votes on Saturday. Each of his rivals received 1 in 10 or less of their votes from Mormons.
Romney won among all non-Mormon voters as well, though by a far narrower margin, capturing around 4 in 10 of their votes. Romney triumphed among Protestants and carried a slight majority of Catholics.
Gingrich and Texas Rep. Ron Paul each took about 1 in 4 of Saturday's non-Mormon voters.
Romney won decisively among the nearly half of voters saying they most wanted a candidate who can defeat Obama in this fall's election. He won about three quarters of their votes — four times as many as went to Gingrich, his nearest competitor on that question.
Coming up: From Nevada, the calendar turns to caucuses in Minnesota and Colorado and a nonbinding primary in Missouri on Tuesday. Maine caucuses end next Saturday, and the next seriously contested states are expected to be primaries in Michigan and Arizona on Feb. 28.