Clinton will hope the victory gives her momentum in the tight nomination battle with Obama to select the Democratic candidate for the presidential election in November.

'Uplifting campaign'

The two had split the first two contests in Iowa and New Hampshire.

Twnety states hold their primaries on so-called Super Tuesday on February 5.

Clinton and Obama, an Illinois senator, both complained of voting irregularities in the hours before and after the vote in Nevada.

In focus


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Clinton
led polls in the state for months heading into the contest, but Obama had been lifted by the endorsement of a powerful labor union that represents about 60,000 workers in the state's tourist hotels.


"We ran an honest, uplifting campaign in Nevada that focused on the real problems Americans are facing, a campaign that appealed to people's hopes instead of their fears," Obama said in a statement.

"That's the campaign we'll take to South Carolina and across America in the weeks to come."

Low turnout

Romney's convincing win in Nevada followed his breakthrough victory in Michigan last week.

He won 51 per cent, with Ron Paul a distant second on 13 per cent, the same figure as John McCain in third.
 
Romney said Republicans had cast their votes for change, and that he was the man to provide it.
 
"With a career spent turning around businesses, creating jobs and imposing fiscal discipline, I am ready to get my hands on Washington and turn it inside out," Romney said in a statement.

The former governor of Massachusetts issued while he flew to Florida to campaign for that state's primary on January 29.

However Al Jazeera's Kimberly Halkett in South Carolina said many political analysts would not place too much emphasis on Romney's victory given that many of the other candidates did not campaign heavily in Nevada preferring to focus on South Carolina.

Polls closed in South Carolina with an appeal from the McCain campaign team to keep certain voting stations open in the state rejected by a judge.

Halkett said a number of factors including unseasonally cold weather meant a low turnout was likely and may impact on the results.

McCain and Huckabee were expected to be in a head to head race for first place.

Clinton will be hoping for momentum heading into "Super Tuesday" [Reuters]