NORTH CHARLESTON, S.C. (Reuters) - As Bernie Sanders looked to cement his front-runner status in the U.S. Democratic presidential race after his dominant win in Nevada, his rivals sought in rallies on Sunday to blunt his momentum ahead of 15 nominating contests in the next 10 days.

Sanders, an independent senator from Vermont and self-avowed democratic socialist, rode a wave of support across age, race and ideology to capture 47% of the county convention delegates in the Nevada caucuses, with 88% of precincts reporting.

Former Vice President Joe Biden, who had lacklustre performances in the first two nominating contests in Iowa and New Hampshire, secured a second-place finish in Nevada, according to a projection by NBC News. But he trailed Sanders by a wide margin, likely to finish more than 20 percentage points behind once all the votes are tallied.

Pete Buttigieg, the former mayor of South Bend, Indiana, who won in Iowa and finished second in New Hampshire, appeared to secure third place in Nevada with 13.6%. If the final results keep Buttigieg below 15%, he may fail to win delegates, the key to securing the nomination.

Sanders’ latest victory is sure to stoke more concern among establishment Democrats who see him as too liberal to defeat Republican President Donald Trump in November. Now they have an additional worry that he may soon be unstoppable in his quest to win the nomination.

But the results in Nevada and the outlook for coming contests are doing little to push the rest of the field to drop out, leaving a cluster of more centrist candidates to divide the anti-Sanders vote and unable to build their own momentum.

Biden, a onetime front-runner in the Democratic race, is hoping to get a boost on Wednesday, when, according to a media report, he will pick up the endorsement of Representative Jim Clyburn, the highest-ranking African American in Congress, who represents a district in South Carolina, a state where voters head to the polls on Saturday in the next Democratic nominating contest.

Buttigieg’s campaign sent a letter, which was seen by Reuters, to the Nevada Democratic Party on Sunday urging it to release data on early voting results, fix errors that might have arisen when counting absentee ballots and explain discrepancies the campaign found before any final tally is announced.

A representative for the state party said the campaigns understood how the reporting process would work before Saturday.

“We are continuing to verify and to report results,” the representative said in a statement. “We never indicated we would release a separate breakdown of early vote and in-person attendees by precinct and will not change our reporting process now.”

‘OWN THIS ELECTION’

Sanders’ triumph on Saturday in the first racially diverse state in the campaign suggested he was reaching a broader coalition of Democratic voters with his unapologetic message of social and economic justice, including his signature pledge to provide universal healthcare for all Americans.

“Together we will defeat the most dangerous president in the modern history of this country,” Sanders told a cheering throng of supporters in Houston. At a later rally in Austin, Texas, he picked up the endorsement of former rival Marianne Williamson, a self-help guru who made an unsuccessful bid for the nomination.

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Biden hopes a possible endorsement by Clyburn, his record on civil rights and eight years as No. 2 to Barack Obama, the first black U.S. president, will appeal to South Carolina’s many African-American voters ahead of Saturday’s primary.

“I don’t expect anything. I am here to earn your vote,” Biden said at Royal Missionary Baptist Church in North Charleston. “You can own this election. It’s yours to determine.”

His advantage among black voters in the state has been eroded by Sanders and activist billionaire Tom Steyer.

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After he failed to qualify for the last debate, Tuesday’s debate in South Carolina will include Steyer, who appeared likely to finish fifth or sixth in Nevada. Steyer qualified with a new CBS/YouGov poll showing that 18% of South Carolina voters favoured him, placing him third.

Biden led the poll with 28%, with Sanders close behind at 23%.

‘FIGHTING IS THE POINT’

In Nevada, Senator Elizabeth Warren, who had been looking to jump-start her campaign after poor finishes in Iowa and New Hampshire, trailed in a disappointing fourth place, while Senator Amy Klobuchar was likely to finish fifth or sixth.

Warren campaigned on Sunday in Colorado, one of the 14 Super Tuesday states where Democratic voters will cast ballots on March 3 to pick more than one-third of the pledged delegates who will help select a Democratic nominee.

She took an aggressive stance against Sanders, arguing that she would be better able to push legislation on climate change and creating a wealth tax.

“Bernie supports the filibuster, but I want to get rid of the filibuster because I want to get something done,” Warren said, referring to the Senate rule that lets a minority of the chamber block legislation.

Klobuchar was in Super Tuesday states Arkansas and Oklahoma, after visiting North Dakota, which holds a Democratic caucus on March 10. Buttigieg spoke in Virginia, yet another Super Tuesday state.

He too swiped at Sanders.

“I don’t think we can allow ourselves to get to the point where it feels like fighting is the point,” he said. “Politics may be fierce sometimes but it’s not just about combat.”