Bernie Sanders scored a resounding victory in Nevada's presidential caucuses on Saturday, cementing his status as the Democrats' national front-runner amid escalating tensions over whether he's too liberal to defeat U.S. President Donald Trump.

While Sanders scored a strong victory, a cluster of candidates fought for a distant second place — and any momentum that may come with it heading into next-up South Carolina and then Super Tuesday on March 3. Joe Biden, Pete Buttigieg and Elizabeth Warren were trailing far behind Sanders.

Sanders had 47 per cent of the county convention delegates in Nevada with 50 per cent of the precincts reported. Biden was a distant second to Sanders with 19 per cent, but ahead of Buttigieg in third place with 15 per cent.

Warren, who had been looking to jump-start her campaign after poor finishes in the first two states, was again trailing in a disappointing fourth with more than 10 per cent in

Nevada, where voters poured into more than 250 sites around the state. Sen. Amy Klobuchar and activist billionaire Tom Steyer were well back at around 4 per cent.

In a show of confidence, Sanders left Nevada for Texas, which offers one of the biggest delegate troves in just 10 days on Super Tuesday.

"We are bringing our people together," he declared."In Nevada we have just brought together a multigenerational, multiracial coalition which is not only going to win in Nevada, it's going to sweep this country."

The win built on Sanders' win earlier this month in the New Hampshire primary. He essentially tied for first place in the Iowa caucuses with Buttigieg, the former mayor of South Bend, Ind., who has sought to position himself as an ideological counter to Sanders' unabashed progressive politics but was fighting for a distant second place in Nevada.

The victory, while encouraging for Sanders supporters, only deepens concern among establishment-minded Democratic leaders who fear that the self-described democratic socialist is too extreme to defeat Trump.

Sanders supporters are seen during a rally in El Paso on Saturday. (Briana Sanchez/The El Paso Times via AP)

Sanders for decades has been calling for transformative policies to address inequities in politics and the economy, none bigger than his signature "Medicare for All" health care plan that would replace the private insurance system with a government-run universal system.

Trump gloated on social media, continuing his weeks-long push to sow discord between Sanders and his Democratic rivals.

"Looks like Crazy Bernie is doing well in the Great State of Nevada. Biden & the rest look weak," Trump tweeted. "Congratulations Bernie, & don't let them take it away from you!"

Buttigieg, Biden take aim at Sanders

Buttigieg congratulated Sanders, too, but then launched an aggressive verbal assault on the senator as too divisive.

"Before we rush to nominate Sen. Sanders in our one shot to take on this president, let's take a sober look at what is at stake for our party, for our values and for those with so much to lose," he said. "Sen. Sanders believes in an inflexible, ideological revolution that leaves out most Democrats, not to mention most Americans."

Biden also took aim at the Vermont senator as he claimed a success — but not a victory — in Nevada that would trigger a comeback.

Democratic presidential candidate and former vice-president Joe Biden greets voters at Cheyenne High School in North Las Vegas on Saturday. (Shannon Stapleton/Reuters)

Without naming names, he took a swipe at Sanders and billionaire Michael Bloomberg, who wasn't on the Nevada ballot but has emerged as a threat to Biden in contests that begin next month.

"I ain't a socialist. I'm not a plutocrat. I'm a Democrat," Biden declared.

Democratic presidential candidate and Massachusetts Sen. Elizabeth Warren greets a young person while visiting a caucus site at Coronado High School in Henderson, Nev., on Saturday. (David Ryder/Reuters)

Klobuchar, campaigning in her home state of Minnesota Saturday night, claimed Nevada success no matter what. "As usual I think we have exceeded expectations."

New York billionaire Mike Bloomberg, who dominated the political conversation this week after a poor debate-stage debut, wasn't on the ballot. He's betting everything on a series of delegate-rich states that begin voting next month.

Nevada avoids Iowa-like chaos

After the chaos of Iowa's caucuses, there were concerns about Nevada's similar setup. But no major problems were in sight.

At noon, under sunny skies, dozens of uniformed housekeepers and casino workers cast ballots in the Bellagio, one of seven casino-resorts on the Las Vegas Strip among 200 locations statewide that hosted caucuses. Nevada is the third contest on a 2020 election calendar marked by chaos and uncertainty after the opening votes in Iowa and New Hampshire, overwhelmingly white, rural states.

The first presidential contest in the West is testing the candidates' strength with black and Latino voters for the first time in 2020. Nevada's population aligns more with the U.S. as a whole, compared with Iowa and New Hampshire: 29 per cent Latino, 10 per cent black and 9 per cent Asian American and Pacific Islander.

The Nevada verdict represents the third in a primary season that will span all 50 states and several U.S. territories, ending only at the party's national convention in July. But with two more rounds of voting scheduled over the next 10 days — including Super Tuesday's massive delegate haul — the party may identify a consensus candidate long before the convention.

The stakes were high for Nevada Democrats to avoid a repeat of the chaos in Iowa, and it appeared Saturday's caucuses were largely successful.

Unlike state primaries and the November election, which are run by government officials, caucuses are overseen by state parties.

A precinct leader records votes at a caucus location at Coronado High School in Henderson, Nev., on Saturday. (Patrick Semansky/Associated Press)

Nevada Democrats sought to minimize problems by creating multiple redundancies in their reporting system, relying on results called in by phone, a paper worksheet filled out by caucus organizers, a photo of that worksheet sent in by text message and electronic results captured with a Google form.

In addition, it appeared Nevada Democrats were able to successfully navigate a complicated process for adding early voting to the caucus process.

Nearly 75,000 people cast early ballots over a four-day period, and the party was able to process those in time for Saturday so they could be integrated into the in-person vote.

People hold up presidential preference cards during the Democratic caucus at the Bellagio hotel-casino on Saturday in Las Vegas. (John Locher/Associated Press)

At the Bellagio caucus site, 41-year-old Christian Nielsen, a scuba diver for the Cirque du Soleil show O, said he backed Sanders because he believes the country needs a "major change in the White House."

"We need somebody in the White House who has been on the right side of history for their entire career, somebody who stands with the working class, and will make things more fair for everybody," Nielsen said.

The Democrats' 2020 nomination fight shifted beyond Nevada even before the final results were known.

Only Biden, Buttigieg and Steyer were still in the state when news of Sanders' victory was announced.

Sanders and Klobuchar spent the night in Super Tuesday states. And Warren, who began Saturday in Las Vegas, was to finish the day in Washington state, which hosts its election on March 10 but has already begun offering early voting.