Saturday's win built on Sanders' victory 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, Indiana, who has sought to position himself as an ideological counter to Sanders' unabashedly progressive politics.
But for all the energy and attention devoted to the first three states, they award only a tiny fraction of the delegates needed to capture the nomination. After South Carolina, the contest becomes national in scope, putting a premium on candidates who have the resources to compete in states as large as California and Texas.
While Sanders' victory in Nevada encouraged his supporters, it only deepened concern among establishment-minded Democratic leaders who fear he is too extreme to defeat Trump. 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 program.
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 congratulated Sanders, too, but then launched an aggressive verbal assault on the senator as too divisive.
"Before we rush to nominate Senator 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. "Senator Sanders believes in an inflexible, ideological revolution that leaves out most Democrats, not to mention most Americans."
For Biden, a second place finish in Nevada could be the lifeline he needed to convince skeptics he still has a path to the nomination as the primary moves to more diverse states. He took aim at Sanders and billionaire Mike 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.
Warren, who desperately needed a spark to revive her stalled bid, ignored Sanders and instead took a shot at Bloomberg's height as she thanked Nevada "for keeping me in the fight."
Rallying supporters in Seattle, she said she wanted to talk about "a big threat — not a tall one, but a big one: Michael Bloomberg."
Also still in the fight: Billionaire Tom Steyer, who spent more than $18 million on Nevada television and Amy Klobuchar, who hoped to prove her strong New Hampshire finish was no fluke.
Klobuchar, campaigning in her home state of Minnesota Saturday night, claimed Nevada success no matter her poor showing.
"As usual I think we have exceeded expectations," she said.
The first presidential contest in the West tested 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% Latino, 10% black and 9% Asian American and Pacific Islander.
Bloomberg, the former New York mayor 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.
The stakes were high for Nevada Democrats to avoid a repeat of the chaos in the still-unresolved Iowa caucuses, and it appeared Saturday's contest was largely successful.
Unlike state primaries and the November election, which are run by government officials, caucuses are overseen by state parties.
Nevada Democrats sought to minimise problems by creating multiple redundancies in their reporting system, relying on results called in by phone, a paper worksheet filled out by caucus organiser's, 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.
At the Bellagio casino 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 Buttigieg was headed to a third, Virginia. 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.
- AP