Senator Bernie Sanders claimed a major victory in the Nevada caucuses on Saturday that demonstrated his broad appeal in the first racially diverse State in the presidential primary race and established him as the clear front-runner for the Democratic nomination.

In a significant show of force, Mr. Sanders, a liberal from Vermont, had a large lead over his nearest rivals in early tallies, and The Associated Press named him the winner on Saturday evening.

His triumph in Nevada, after strong performances in Iowa and New Hampshire, will propel him into next Saturday’s primary in South Carolina, and the Super Tuesday contests immediately thereafter, with a burst of momentum that may make it difficult for the still-fractured moderate wing of the party to slow his march.

Mr. Sanders, speaking to jubilant supporters in San Antonio, trumpeted what early results suggested would be a landslide victory.

“We have just put together a multigenerational, multiracial coalition, which is not only going to win in Nevada it’s going to sweep the country,” he said, predicting another victory in Texas next month.

While Mr. Sanders boasted that “no campaign has a grassroots movement like we do,” and was bathed in “Bernie, Bernie!” chants, he otherwise ignored his Democratic opponents.

Mr. Sanders’ success, and the continued uncertainty over who is his strongest would-be rival, makes it less clear than ever how centrist forces in the party can organise themselves for a potentially monthslong nomination fight. The moderate wing is still grappling with an unusually crowded field for this late in the race, the lack of an obvious single alternative to Mr. Sanders and no sign that any of those vying for that role will soon drop out to hasten a coalescence.

As results were being counted Saturday night, former Vice-President Joe Biden, former Mayor Pete Buttigieg of South Bend, Indiana, Sen. Elizabeth Warren of Massachusetts, billionaire investor Tom Steyer and Sen. Amy Klobuchar of Minnesota were all competing for what would clearly be a distant second-place finish.

With the full order of finish still in doubt, Mr. Buttigieg used his caucus-night speech to deliver a stern warning about the implications of nominating Mr. Sanders, urging Democrats not to “rush” into anointing him as their candidate.

“Sen. Sanders believes in an inflexible, ideological revolution that leaves out most Democrats, not to mention most Americans,” Buttigieg said, adding that Sanders wanted to “reorder the economy in ways most Democrats, not to mention most Americans, don’t support.”

Mr. Biden appeared at a Las Vegas union hall while most votes were still uncounted to claim a comeback and vowed victory in South Carolina. “Y’all did it for me,” he told supporters, trying out a new line aimed at his rivals. “I ain’t a socialist, I ain’t a plutocrat, I’m a Democrat.”

Mr. Biden’s campaign asserted that he would finish in second place here, a claim challenged by Mr. Buttigieg’s aides.

Time is running out

The apparent scale of Mr. Sanders’ victory margin presented an immediate challenge to the rest of the candidates, many of whom have been counting on a drawn-out nomination fight to give them time to catch up. But time is plainly running short, and few of Mr. Sanders’ rivals have a clear path to closing his advantage. Among them, only Mr. Biden has a realistic chance of winning South Carolina next week, the sole remaining contest before Super Tuesday on March 3. NY Times