DES MOINES, Iowa (AP) — Clouded by doubts on a chaotic day-after, Democratic Party officials planned to release a majority of Iowa's delayed presidential caucus results by late Tuesday, according to details shared with campaigns on a private conference call.

The news did little to stem rising confusion and concern more than 12 hours after voting ended without the release of a single result in the opening contest of the Democrats 2020 primary season.

State party chairman Troy Price informed campaigns that he would release at least 50% of all caucus results at 5 p.m. EST, but he declined to answer pointed questions from frustrated campaign representatives about when the party would release the full results or how it could ensure their integrity -- even whether it would be a matter of days or weeks.

"We will continue to work through the process," Price said on the call, which was monitored by The Associated Press. "We want to get some results out there."

At the same time, the leading candidates tried to spin the uncertainty to their advantage — as did billionaire Democrat Michael Bloomberg, who vowed to double his already massive advertising campaign and expand his sprawling staff.

Campaigning in New Hampshire on Tuesday, Sen. Elizabeth Warren said she was "feeling good" about her performance in Iowa but questioned the state party's plans to release partial results.

"I just don't understand what that means, at least half of the data. I think they ought to get it together and release all the data," she said.

Vermont Sen. Bernie Sanders' campaign told supporters that its internal monitoring showed him in the lead with nearly half the vote in. Sanders himself said late Monday, "Today marks the beginning of the end for Donald Trump."

Pete Buttigieg, the former mayor of South Bend, Indiana, essentially declared an Iowa  victory.

"So we don't know all the results, but we know by the time it's all said and done, Iowa, you have shocked the nation," he said before leaving Iowa. "By all indications, we are going on to New Hampshire victorious."

Shortly before boarding a flight to New Hampshire, former Vice President Joe Biden said he was "feeling good" and predicted the results would be close.

The party's caucus crisis was an embarrassing twist after months of promoting the contest as a chance for Democrats to find some clarity in a jumbled field with no clear front-runner.

Instead, caucus day ended with no winner, no official results and many fresh questions about whether Iowa can retain its coveted "first" status.

The party told campaigns Tuesday that the problem was a result of a "coding issue in the reporting system" that it said had since been fixed. It said it had verified the accuracy of the collected data and said the problem was not a result of "a hack or an intrusion."

Still, there were signs that the process was ongoing and laborious.

Price confirmed that party officials were sending volunteers and staffers across the state to retrieve hard-copy results so they could check them against numbers reported from precincts via a mobile app that proved problematic for many users.

Tuesday's conference call was tense at times.

A Biden campaign representative objected to the state party's plan to release partial results before checking them against paper records, saying on the conference call that the plan didn't address "growing reports" about problems on caucus night, such as precinct captains unable to get through on the phone to report results.

"The stories and the problems are just multiplying so presumably you're going to have some way of addressing that and explaining to us as you release these partial results why you're comfortable," Biden campaign attorney Dana Remus said. "You need to have enough transparency that other people feel comfortable about it now and we're just not there right now."

Other campaigns supported the party's decision. Sanders adviser Jeff Weaver thanked party officials, and encouraged other campaigns not to undermine the party.

"Folks who are just trying to delay the return of this because of their relative positioning in the results last night, I think that's a bit disingenuous," Weaver said.

Sensing opportunity amid the chaos, Bloomberg's campaign announced plans to double its national television advertising spending — which has already exceeded $100 million — as it expands its paid staff to more than 2,000 people.

Bloomberg is looking to next month, having decided to bypass Iowa's contest and the three other states voting this month in favor of the delegate-rich states in March.

"After more than a year of this primary, the field is as unsettled as ever," Bloomberg spokeswoman Sabrina Singh said. "No one has made the sale or even come close to it. Meanwhile, Mike is taking the fight to Trump every day, doubling down on the national campaign strategy we've been running from the beginning."

Beyond 2020, the debacle invited fresh criticism about Iowa caucuses, a complicated set of political meetings staged in a state that is whiter and older than the Democratic Party. Many used the moment to question whether it was a quaint political tradition whose time had passed.

The party has tried to accommodate critics before, this year by promising to report three different data points about voters' preferences, presumably improving transparency. But the new system created new headaches.

State party spokeswoman Mandy McClure said it had "found inconsistencies in the reporting of three sets of results," forcing officials to try to verify results with "underlying data" and the paper trail.

Some of the trouble stemmed from the buggy app. Organizers at caucuses site reported trouble downloading the app and other glitches. Many turned to a back-up phone system.

The confusion played out a day after Iowa Democrats across the state cast their votes, balancing a strong preference for fundamental change with an overwhelming desire to defeat Trump. At least four high-profile candidates vied for the lead in a contest that offered the opening test of who and what the party stands for in the turbulent age of Trump.

It's just the first in a primary season that will span all 50 states and several U.S. territories, ending at the party's national convention in mid-July.

For Democrats, the moment was thick with promise for a party that has seized major gains in states since Trump won the White House in 2016. But instead of clear optimism, a growing cloud of uncertainty and intraparty resentment hung over the election as the prospect of an unclear result raised fears of a long and divisive primary fight in the months ahead.

The president eagerly seized on the Democrats' problems.

"The Democrat Caucus is an unmitigated disaster," Trump tweeted Tuesday. "Nothing works, just like they ran the Country." He added: "The only person that can claim a very big victory in Iowa last night is 'Trump.'"

Pre-caucus polls suggested Sanders entered the night with a narrow lead, but any of the top four candidates — Sanders, Biden, Warren and Buttigieg — was positioned to score a victory. Sen. Amy Klobuchar, who represents neighboring Minnesota, was also claiming momentum, while outsider candidates including entrepreneur Andrew Yang, billionaire activist Tom Steyer and Hawaii Rep. Tulsi Gabbard could be factors.

New voters played a significant role in shaping Iowa's election.

About one-quarter of all voters reported that they were caucusing for the first time, according to AP VoteCast, a survey of voters who said they planned to take part in Monday's Democratic caucuses. The first-timers were slightly more likely to support Sanders, Warren or Buttigieg, compared with other candidates.

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