(Updates results, Fox News projection)
LAS VEGAS, Feb 22 (Reuters) - Bernie Sanders appeared headed to a decisive victory in the Democratic presidential caucuses in Nevada on Saturday, and early returns showed Joe Biden landing a second-place finish that would give his struggling campaign new hope.
Fox News projected Sanders as the winner in Nevada, where scattered early returns showed him opening up a dominating lead with about 5% of votes in.
Sanders, a U.S. senator from Vermont, will gain fresh momentum for his front-running candidacy in the Democratic White House race with the win in Nevada, where he was buoyed by what entrance polls showed was strong support for a government-run Medicare for All healthcare plan like the one he has proposed.
Biden, the former vice president, had been in desperate need of a strong showing after poor finishes in the first two contests in Iowa and New Hampshire.
Biden was a distant second to Sanders, but ahead of former Mayor Pete Buttigieg of South Bend, Indiana, in third.
Senator Elizabeth Warren was fourth in scattered results in Nevada, where voters poured into more than 250 sites around the state to make their pick for a Democratic challenger to President Donald Trump in the Nov. 3 election.
In the final result of a caucus at the famed Bellagio hotel on the Las Vegas strip, Sanders finished with 76 votes, Biden had 45 and no other candidate ended with a vote.
Workers at the hotel, who are members of the Culinary Workers Union, streamed out of the caucus after backing Sanders despite their leadership expressing reservations about his healthcare plan.
"I went for Bernie. I'm not big into politics, but I like the things he's going for: student loan debt, schools, free healthcare," said Aleiza Smith, 22, a housekeeper at the Bellagio.
An entrance poll by the Edison Research agency showed six in 10 Nevada voters at the caucuses backed the Medicare for All proposal, a version of which is also supported by Warren.
Six out of 10 caucus-goers want someone who can beat Trump more than someone who agrees with them on major issues, according to the poll.
Sanders, a self-identified democratic socialist, has surged to the top of opinion polls nationally and in Nevada after strong performances in the first two nominating contests in Iowa and New Hampshire earlier this month.
The Nevada caucuses came a day after news broke that Sanders had been briefed by U.S. officials that Russia was trying to help his campaign as part of an effort to interfere with the 2020 presidential election.
The poll showed Sanders leading in Nevada with Hispanics, union families, and white college-educated women. Around 54% of Latino voters said they backed him, while 24% of college-educated white women and 34% of those who have a union member in their families supported him.
While Sanders' rivals will try to blunt his momentum in the caucuses, they each face significant challenges of their own.
Biden and Warren are looking to jump-start struggling campaigns after poor finishes in the first two states, while former Buttigieg and Senator Amy Klobuchar are hoping to prove they can appeal to Nevada's more diverse electorate.
On Friday evening, Sanders spoke to about 2,000 people in Las Vegas, revving up the crowd with vows to take on "the corporate elite" and the "whole damn 1%".
Trump, who lost Nevada to Democrat Hillary Clinton in 2016, tweeted on Saturday that he expected to win in Nevada in the general election in November and alluded to the reports that a Russian disinformation effort was supporting Sanders.
Four days of early voting in Nevada this week drew more than 75,000 Democrats, more than half first-time voters, putting the party in position to surpass the turnout record of 118,000 in 2008, when Barack Obama's candidacy electrified the party.
After days of delay and mistrust caused by a technical meltdown during the Iowa caucuses, Nevada Democratic Party officials said in a memo to campaigns on Friday that a telephone hotline many volunteers "were already familiar with" would be the main method of reporting precinct caucus results, not digital tools.
Precinct chairs will also text a photo of their caucus reporting sheet as part of efforts to strengthen the processes.
At a Democratic debate in Nevada on Wednesday, candidates launched scathing attacks on Michael Bloomberg, the billionaire former mayor of New York City, who has been rising in the polls on the back of a self-funded advertising blitz but is not competing in Nevada.
Warren's campaign said on Saturday it had raised $14 million ahead of the caucuses, double a target it had set after a lackluster performance in New Hampshire, and fueled by donations following her fiery debate barrage aimed at Bloomberg.
The next primary will be on Feb. 29 in South Carolina, followed by the Super Tuesday contests in 14 states on March 3 that pick more than one-third of the pledged delegates who will help select a Democratic nominee.
Nevada is the first nominating state with a diverse population after contests in predominantly white Iowa and New Hampshire.
(Writing by John Whitesides and Michael Martina; Additional reporting by Sharon Bernstein, Jane Ross and Elizabeth Culliford; Editing by Soyoung Kim, Alistair Bell, Cynthia Osterman and Sandra Maler)