LAS VEGAS — Early voting for Nevada’s Democratic caucuses began on Saturday, with several leading candidates rallying supporters amid lingering concerns about whether Nevada would be able to avoid a repeat of the caucus fiasco in Iowa.
So, for example, when Senator Bernie Sanders of Vermont addressed a crowd in a high school cafeteria on Saturday, with a mariachi band taking the stage before he did, his supporters were sharply focused on the process as well as on Mr. Sanders and his opponents.
Numerous people expressed concern about the logistics of a caucus that they want to deliver a speedy and unequivocal victory to their candidate.
“I went to a training last week, and there are lots of concerns among the campaign: ‘How’s it actually going to work?’” said Paul Kleemann, a precinct captain volunteer for the Sanders campaign who teaches high school guitar in Las Vegas. “We were supposed to use the same app as Iowa, but they scrapped that, and as of Wednesday they hadn’t released how they were going to get the early caucus results to the precincts.” He added: “It’s a little frightening at this point.”
In Nevada, early voting is being held from Saturday through Tuesday in advance of next Saturday’s caucuses. Democratic officials in the state are under pressure to avoid the debacle in Iowa that delayed and muddied the reporting of results from the first nominating contest.
After initially planning to use a similar phone app to what was used in Iowa to tabulate vote and transfer data, Nevada officials have instead said that they would distribute iPads to caucus chairs, and rely on online response forms submitted through Google to calculate and tabulate the results of the caucuses.
But the early caucuses are new this year and party officials have still not made clear how they plan to give precinct chairs the results during the in-person caucuses. For early caucusing, voters are asked to rank their top three choices on a form that allows them to list up to five.
Those forms will be tabulated by party officials, and the results will be distributed to precinct chairs during the caucus next Saturday. Presidential campaigns and caucus volunteers have expressed frustration that they still do not have clear guidance on many details about how the results will be recorded and reported to the public.
Several officials from the Democratic National Committee have flown to Las Vegas in the past week to help the state party, which has repeatedly expressed confidence that the caucuses will unfold without problems.
“This is the first time we’ve done early voting, and we’ve got to get this right because all eyes are on Nevada,” Representative Dina Titus, Democrat of Nevada, said on Friday. “And if we do a good job, then maybe we get to be first instead of Iowa next time around.”
Mr. Sanders came into the weekend riding high, having emerged from New Hampshire with a victory in this past week’s primary, and he was one of several candidates who sought to rally supporters in the state on Saturday.
The burst of campaigning in Nevada signaled a new phase in the primary race, after the Iowa caucuses on Feb. 3 and the New Hampshire primary this past Tuesday. The candidates have now plunged into a pivotal and chaotic portion of the calendar, with critical contests coming up in Nevada and South Carolina, and a slew of contests looming on Super Tuesday in early March.
Former Vice President Joseph R. Biden Jr., who is seeking to stabilize his campaign with a strong showing in Nevada after weak performances in Iowa and New Hampshire, began his day by visiting a barber school, where he went from barber chair to barber chair greeting people. Then he addressed supporters in a middle school gym, where he was joined by several elected officials, including Mayor Eric M. Garcetti of Los Angeles, a national co-chair of Mr. Biden’s campaign.
As she fights to build on momentum coming out of New Hampshire, Senator Amy Klobuchar of Minnesota began her day in the suburb of Henderson, speaking inside a wedding event center tucked into a strip mall. She said she had received more than $3 million in online donations since the New Hampshire primary.
As she often does, Ms. Klobuchar focused on her image as a moderate, taking a swipe at Mr. Sanders.
“I think I was the only one that raised my hand and said, ‘You know, I have some trouble with having our ticket led by socialism,’” she said.
At an early caucus site at the East Las Vegas Library, voters waited in a 40-minute line on Saturday morning, the first year they have had the option to caucus early.
Much of the interest was directed toward someone not on the Nevada ballot.
Linda Vaganov, a Navy Reserves veteran who is on disability, said she voted for Amy Klobuchar but really wants former New York Mayor Michael R. Bloomberg to be the nominee.
She said Mr. Bloomberg has the money and street-fighting instincts to defeat President Trump. “I don’t see Biden as the street fighter that Bloomberg is,’’ she said. “When I saw Bloomberg’s tweets to Trump, I thought, this guy can get down and dirty and still look dignified.”
Another voter who said he hopes Mr. Bloomberg is the nominee, Byron Brewer, voted for Mr. Biden.
“Between you and me and the fence post,’’ he said, “it will probably all settle out to Bloomberg.’’ He added: “He’s the big dog as far as his money, “It’s just going to be the worst kind of gutter fight you can imagine, and you might as well have all that money on your side.’’
One interested observer at the same site was Harry Reid, the former Senate majority leader and long the state’s most powerful Democrat.
Mr. Reid, who appeared in a wheelchair, has not endorsed a Democrat in the race and generally praised all of the candidates he was asked about.
He said it was “way too early to count Joe Biden out” and shrugged off a question about whether Mr. Sanders would hurt down-ballot Democrats.
“Well they’ve been saying that about Bernie since long before he started running,” he said, adding that “All the polls show that if he becomes the nominee, he will beat Trump.”
Asked about Mr. Bloomberg, Mr. Reid said: “Mayor Bloomberg came to my home. I met him, of course, when I was the leader. I like him a lot.” He added: “He was a good mayor. No one in the country, no one, has done more on guns and climate than Mayor Bloomberg.”
Trip Gabriel contributed reporting.