DES MOINES — The winner of Iowa’s first in the nation Democratic presidential caucus remained elusive early Tuesday morning as the clock struck midnight local time without the state party having reported any results of the prior evening’s caucus.

Reports surfaced on social media Monday evening about confusion caused by a new, optional app the Iowa State Democratic Party created for precinct chairs to report the results of their individual caucuses and jammed phone lines overwhelmed by caucus leaders trying to report their results through the traditional method. The party, meanwhile, attributed the delay to a new requirement, established by the Democratic National Committee, that they report several sets of caucus result numbers publicly.

The change this year, which will also apply to Nevada’s Feb. 22 Democratic caucus, requires for the first time the reporting of raw totals of caucusgoers who supported each candidate in addition to delegate totals, which determine how many representatives the state will send to the Democratic National Convention on each candidate’s behalf. The party planned to release the raw totals of both the first alignment, which represents a voter’s first choice, and the second alignment, which allows supporters of candidates that didn’t receive a high enough level of support to qualify for delegates, to choose a different candidate to back.

Iowa State Democratic Party spokeswoman Mandy McClure said in a statement late Monday night that the party had identified “inconsistencies” between the sets of results reported, and was working to verify the reported results through photos of results and a physical paper trail of presidential preference cards.

“This is simply a reporting issue,” McClure said. “The app did not go down and this is not a hack or an intrusion. The underlying data and paper trail is sound and will simply take time to further report the results.”

The reporting fiasco has already begun to cast doubt on Nevada’s Democratic presidential caucus, scheduled to be held later this month, which also leans heavily on the use of two new caucus apps. Nevada Democrats plan to allow voters cast their presidential preferences on a tablet during a four day early-voting period that runs from Feb. 15 to 18, and will also have a Caucus Day reporting app used by precinct captains to submit the results of the caucus.

The Nevada State Democratic Party has not publicly named the vendor it used to develop its apps, but campaign finance reports filed with the Federal Election Commission reveal a $58,000 payment to the political technology company Shadow Inc. for “technology services.” The Iowa Democratic Party also paid Shadow a little more than $63,000 for “professional fees” in November and December. A spokeswoman for the Nevada State Democratic Party declined to comment about the work that Shadow performed for the party.

However, Iowa’s app was largely shrouded in secrecy ahead of Monday’s caucus, and the existence of the app itself was only announced in January. The Nevada State Democratic Party, by contrast, has long planned to use an app as part of its caucus process, and party officials shared screenshots with and provided extensive details of how the app is supposed to function in December to The Nevada Independent, contemporaneously with beginning to train their volunteers on how to use the apps using those screenshots.

The fact that no results were reported Monday night, however, allowed Democratic presidential hopefuls to all claim varying forms of victory out of the first in the nation caucus. Former Vice President Joe Biden, whose support looked shaky heading into Caucus Night, said that he and his campaign “feel good about where we are.”

“So it’s onto New Hampshire. Nevada. South Carolina and well beyond,” Biden told supporters at Drake University Monday evening. “We’re in this for the long haul.”

Biden’s campaign, however, sent a caustic letter to the Iowa State Democratic Party Monday evening, declaring “acute failures” by the state party.

“We appreciate that you plan to brief the campaigns momentarily on these issues, and we plan to participate,” the letter said. “However, we believe that the campaigns deserve full explanations and relevant information regarding the methods of quality control you are employing, and an opportunity to respond, before any official results are released.”

Vermont Sen. Bernie Sanders, who was favored heading into Monday evening, came as close to declaring victory as he could without having actually seen any official results.

“Let me begin by stating that I imagine, have a strong feeling, that at some point the results will be announced and when those results are announced I have a good feeling we’re going to be doing very very well here in Iowa,” Sanders told supporters at a Holiday Inn near Des Moines Airport.

Former South Bend Mayor Pete Buttigieg also proclaimed victory, speaking to supporters at Drake University.

“Tonight, improbably, hope became an undeniable reality,” Buttigieg said.

Minnesota Sen. Amy Klobuchar, the first to take the stage Monday evening, said that her campaign was “punching above its weight.”

“I did not want to let another minute go by without thanking all of you,” Klobuchar said. “My heart is full tonight.”

Massachusetts Sen. Elizabeth Warren didn’t declare victory, telling supporters at the Forte Banquet and Conference Center in downtown Des Moines that it was “too close to call” but that she would share with them “what I do know,” pivoting to a version of her stump speech.

The candidates now head to New Hampshire to campaign ahead of that state’s Feb. 11 first in the nation primary contest.