LAS VEGAS — A new early-voting system, high turnout and questions about a never-before-used digital tool being used to process results could threaten the success of the Nevada Democratic caucuses on Saturday, election experts told NBC News.

"I don't see how any technologist or any party official or any political scientist can promise that this will turn out OK," said Mark Lindeman, the director of science and technology policy for Verified Voting, a nonpartisan nonprofit group that advocates for election accuracy and transparency.

"There are too many tools and procedures that are being rolled out, some at the last minute," he continued. "And my impression is that the people on the ground who are charged with implementing these procedures and using these tools are not confident they can do it."

Lindeman added, "I hope that it goes better than Iowa, but it is definitely at risk for similar reasons."

Tom Perez, the chairman of the Democratic National Committee, would not even commit to releasing the results of the caucus on Saturday after the contest concluded, telling the Associated Press he prized accuracy over speed.

"We're going to do our best to release results as soon as possible, but our North Star, again, is accuracy," Perez said.

In Nevada, several factors are at play that contribute to the possibility that things will go awry, turning it into another debacle like the tabulation of the Iowa caucuses.

During the early-voting window from Saturday through Tuesday (a new feature for the Nevada caucus), there was a ranked-choice system in place. Early voters had to mark their first choice and at least two additional choices, so that their votes can be realigned if their top choices don't make the cut.

The early votes then get routed to the voter's home precinct, so those votes will be counted alongside neighbors who are voting in person on Saturday.

"I don't want to make this sound even scarier than it is, but they haven't done this before, which makes it scary," Lindeman said.

On Saturday, the voting in the Nevada caucuses will proceed much like Iowa's did.

At most Democratic caucus locations, candidates must have support from at least 15 percent of caucus-goers in each precinct to be considered viable. Once all the attendees finish their first alignment, those with candidates who do make the cut are locked and cannot change their preference. Those who support nonviable candidates can realign with a viable candidate on the second round.

With those results, a formula awards delegates to viable candidates by precinct. Candidates have to hit the 15 percent threshold both in congressional districts and statewide to receive a share of the state's delegates.

The Nevada Democratic Party said it will be using a digital tool they are calling a "caucus calculator" to help process the results. According to state party officials, the tool is a Google Forms program that has been pre-loaded with early vote results specific to that precinct. It's also pre-loaded with formulas that will be used to calculate delegate allocation.

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Caucus volunteers — who staff the precincts and run the caucuses — began receiving hands-on training with iPads that contain the tool on Tuesday. The training will continue until Saturday, according to the Nevada Democratic Party.

Party officials have repeatedly said that nothing used during the Iowa caucuses — including the smartphone app that caused a significant delay in reporting results due to a "coding issue" — will be used during the Nevada caucuses. Officials also said they had independent security experts test the process, but could not say what the testing looked like.

If the iPads fail for any reason, the volunteers will use paper backups.

"I think we have reason to be worried," said Rick Hasen, a professor of law and political science at the University of California-Irvine and the editor of Election Law Blog. "As was the case in Iowa, you have the party doing multiple new things at once. Here, one is new technology, and two is new rules, with the early voting."

"It makes me queasy," he added, calling the system "incredibly complex."

Caucus volunteers will call in results to the state Democratic Party via a "secure, dedicated hotline." However, they're free to use any phone to do this, including personal cellphones and landlines.

In Iowa, the hotline number was found in publicly available materials and posted to the fringe message board 4chan along with encouragement to "clog the lines" with prank calls. People who worked the Iowa hotlines said that they did receive some prank calls, but that it was just a small part of the broader problems of the caucuses.

Experts said a major concern is that the early vote is tallied differently than the live caucus results. Success assumes that the relevant early vote results will be sent properly to the correct precincts to be merged with the live caucus results, and also that the ranked-choice votes will be interpreted correctly by the digital tool, or by caucus volunteers if the digital tool fails.

"One of the biggest challenges is that if they get the early vote totals wrong is that it would contaminate everything," said Lawrence Norden, the director of election reform program at the Brennan Center for Justice in New York.

Added Hasen, "I think it will overwhelm with complexity those people running the caucus."

"The lack of advanced training looms large in my opinion," he said. "When people are interacting with technology they haven't been trained on, it makes them much more prone to mistakes they wouldn't have otherwise made.”

Complicating matters is an expectation of high turnout — meaning the sheer amount of work to be done will be enormous — along with the question of how secure the iPads and the digital tool they contain are.

The Nevada Democratic Party announced Wednesday that more than 77,000 residents participated in early voting. That, of course, does not include the amount of people who will caucus on Saturday, but is very high, compared with the two last Democratic caucuses in Nevada. Total Democratic turnout was about 84,000 for the 2016 Nevada caucus, when there was not early voting. In 2008, when there also was not early voting, turnout was 118,000.

Each iPad will be password-protected and will be connected to the internet via 4G, not WiFi. Greg Miller, the cofounder of Open Source Election Technology (OSET), a nonprofit that conducts election technology research, said that because the Google App suite and Cloud are encrypted, "there is very little likelihood for any data tampering or alteration issues."

NBC News has collaborated with the OSET Institute since 2016 to monitor U.S. election-technology and voting issues.

Nevertheless, Perez, the Democratic chair, said Wednesday morning that he was confident the process would run smoothly.

"I have a lot of confidence in Nevada," Perez told CNN, adding that there had already been more than 1,000 training sessions for 3,000 volunteers. "A really, really strong party. We have gone to school on the lessons of Iowa. We're as low-tech as humanly possible while still preserving efficiency."

In addition, a DNC official told NBC News the party would be sending three dozen people to Nevada by Saturday. The official added that Perez will be in Nevada Saturday for the caucus as well.

Nevada Democratic Party officials said they had scheduled 55 training sessions for caucus volunteers between Wednesday and Saturday, both online and in-person, to help volunteers understand the tool. The party said it had also recruited "additional tech volunteers" to "help facilitate and troubleshoot any issues at sites across the state."

Representatives for the campaigns of Joe Biden, Pete Buttigieg, Amy Klobuchar, Bernie Sanders, and Elizabeth Warren declined to comment about any caucus issues.

With so many questions looming, however, the experts interviewed all suggested that the state and national party start setting expectations the right way.

"Nevada has one big advantage over Iowa, and that is that Iowa happened first," said the Brennan Center's Norden. "They should be prepared that things may go very wrong, and they should be preparing the public for this. It feels much more suspect when there hasn't been advance warning that this could happen."