Three contenders — Joe Biden, Pete Buttigieg and Elizabeth Warren — were polling within a few percentage points of one another ahead of the caucuses, with Amy Klobuchar and Tom Steyer not far behind.

The timing of the results of the caucuses remained unclear, with many Democrats still fearful of a repeat of the chaos in Iowa. At a minimum, the reporting process was expected to take hours, potentially lasting into late Saturday or spilling into Sunday.

Early Saturday, party leaders began sounding alarms that caucus workers weren’t showing at some select sites. Some presidential campaigns were approached to help run the events.

“It has the makings of a shitshow,” said a top advisor to Biden’s campaign. “We’ve been approached to help and we’ll help. But do we really want campaigns involved in tallying votes for the caucus?”

Staffer shortages are an expected problem for caucuses — which are run on shoestring budgets by political parties and not state elections officials — and state and national leaders were ready with reserves to “put out fires. And yes we expected fires,” a Nevada Democratic Party official said.

“To be honest, we’re more worried about the rain depressing turnout. If that happens, the early vote will dictate who wins this,” the official added. The Democratic National Committee dispatched three dozen staffers and flew in loads of volunteers from across the nation, especially California, a neighboring state teeming with party volunteers.

Addressing reporters at a forum on Friday night, AFSCME President Lee Saunders said, “I am very, very hopeful that we will not have the debacle that we had in Iowa.”

He said, “We’re just crossing our fingers.”

Early entrance polls suggested that Sanders has a significant advantage, with roughly a third of caucus-goers saying he was their first choice. The race for second place appears much closer, with Biden, Buttigieg and Warren all running relatively even — and, critically, around the 15 percent viability threshold, with Klobuchar and Steyer close behind.

Sanders was overwhelmingly the top choice for young voters, winning roughly six-in-10 of those under age 45. And he’s also winning about half of Hispanic and Latino caucus-goers, far more than any other candidate.

For Biden, the one-time frontrunner both nationally and in Nevada, the importance of the contest is especially high. Embarrassing finishes in the first two states left his campaign reeling and eroded his once-overwhelming advantage in South Carolina, the next primary state.

A third washout here could be too much for his would-be supporters to endure, presaging a collapse in South Carolina and on Super Tuesday.

Sanders has rapidly overtaken Biden in national polls, and he is now running far ahead of the rest of the field.

Returning to Nevada on Friday night after campaigning in California, Sanders predicted victory in the caucuses “if we come out in big numbers.”

“Change is our mantra,” he said at a rally in Las Vegas. “We are going to change this country.”

If Biden does falter, Nevada could point to an alternative candidate to oppose Sanders and Mike Bloomberg, the centrist billionaire who is not competing here but will factor significantly in the March primaries.

Buttigieg, who finished alongside Sanders at the top in Iowa and ran second to him in New Hampshire, will be tested for the first time in a state with a significant number of people of color, with whom he's made little headway. The same is true of Klobuchar, who has only recently begun developing a national campaign organization after a surprising, third-place finish in New Hampshire.

Elizabeth Warren, who drew praise and raised millions of dollars after her evisceration of Bloomberg in Wednesday’s debate, could revive her candidacy with a strong result.

It was unclear, however, how much that debate would factor in the outcome. Nearly 75,000 Nevadans already cast ballots in early caucusing ahead of the debate. In 2016, when Nevada had not yet instituted early caucusing, about 84,000 people participated.

The caucuses mark a turn in the campaign toward a more nationalized primary, with South Carolina — the last of the four early voting states — coming Feb. 29, just three days before Super Tuesday. The candidates were already looking ahead in recent days, campaigning not only in Nevada, but in nearby Super Tuesday states such as California, Colorado and Utah.

Meanwhile, candidates intensified their efforts to raise the money that they'll need to compete across multiple states. Biden, Buttigieg, Klobuchar and Warren are all strained financially. Klobuchar was planning to hold a fundraiser in Minneapolis on Saturday night. Buttigieg raised money last week in California.

“We have our sights set not just on Super Tuesday, but beyond,” Klobuchar told supporters at a campaign office in Las Vegas on Saturday morning.

Later, she told reporters that the broader landscape “will give me a chance — as our numbers have gone up in the national polls — to get out different voters, and people that maybe don’t always go to caucuses.”

Still, the high number of early votes this year was viewed by Democrats as an encouraging development after turnout fell below expectations in Iowa.

A majority of early voters were first-time caucus-goers, a positive sign for a party seeking evidence of enthusiasm to defeat President Donald Trump. The Nevada Democratic Party said Saturday that more than 10,000 Nevadans registered to vote as Democrats during the four-day early voting period, expanding the party’s registration advantage in the state.

But the encouraging turnout was tempered by concerns about the process.

At Cheyenne High School in Las Vegas, Biden was circumspect when asked about his confidence the caucuses running smoothly. “I’ll tell you that after we get it done. Look, this is a complicated process,” Biden said. “I hope it works out.”

To get more precinct captains in Nevada, the Steyer campaign offered all their staffers who were in Nevada free plane tickets and a hotel to bring a friend to the state to serve in that capacity, according to a Steyer campaign official and another person familiar with the matter. Some of the staffers, but not a majority, took the campaign up on the offer, according to the official.

Sanders adviser Jeff Weaver said Saturday morning the campaign had “not been asked to provide people to run precincts, but our precinct captains are prepared to help out whenever party volunteers are not present.”

Keion Cherry, a precinct chair at Valley High School, said, “I’ve been definitely trying to get any volunteers. We had to get some of the precinct captains to be volunteers.” Cherry added that he had “called my superiors … and they were not responding.”

Molly Forgey, communications director for the state Democratic party, said the party had “been recruiting and training volunteers all the way through this morning to ensure we have the capacity we need and we are confident in having the necessary volunteer numbers to cover caucus sites today.”

Forgey said the party has thousands of volunteers and that shortages were not occurring at a majority of sites. “It's common and not unusual for campaign volunteers to help with running precincts on caucus day — this happened in 2016 and in 2008,” Forgey said.

There are expected to be an average of eight volunteers per caucus site, and more than 2,000 across the state, according to the state party. As of roughly 11:30am Pacific time, more than 1,000 volunteers had logged in to use a Google form, dubbed the caucus calculator, which was saved to an iPad at each precinct.

Holly Otterbein, Alex Thompson, Elena Schneider and Daniel Lippman contributed to this report.