Former Massachusetts governor Mitt Romney secured more than 40 per cent of support in the Nevada caucuses (AP)
Republican presidential front-runner Mitt Romney has cruised to victory in the Nevada caucuses, notching a second straight triumph over a field of rivals suddenly struggling to keep pace.
The caucuses drew little attention in the nominating campaign, but Nevada figures to be a fierce battleground in November between the winner of the Republican nomination and Democrat president Barack Obama. The state's unemployment rate was measured at 12.6% in December, the worst in the US.
Mr Romney unleashed a sharp attack on Mr Obama, whose economic policies he said have "made these tough times last longer".
"President Obama seems to believe America's role as leader in the world is a thing of the past. I believe the 21st century will be and must be an American century," he said to cheers from his backers.
Mr Romney, the former Massachusetts governor, held a double-digit lead over his nearest pursuer as the totals mounted in a state where fellow Mormons accounted for roughly a quarter of all caucus-goers.
Former House of Representatives speaker Newt Gingrich and Texas Rep Ron Paul vied for a distant second. Former Pennsylvania senator Rick Santorum trailed the field. Returns from 14 of 17 counties showed Mr Romney with 42% support, Mr Gingrich with 25%, Mr Paul with 20% and Mr Santorum with 13%.
Mr Romney's victory capped a week that began with his double-digit win in the Florida primary. That contest was as intense as Nevada's caucuses were sedate - so quiet that they produced little television advertising, no candidate debates and only a modest investment of time by the contenders.
According to the AP count, Mr Romney began the day with 87 of the 1,144 delegates needed to win the Republican nomination. Mr Gingrich had 26, Mr Santorum 14 and Mr Paul four.
A total of 28 delegates were at stake in the state-by-state race to lock up the 1,144 needed to secure the Republican nomination.
From Nevada, the calendar turns to caucuses in Minnesota and Colorado and a non-binding 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 February 28.