After a full day of uncertainty, Joe Biden sits in fourth place in the Iowa caucuses, according to the first partial results released by the Iowa Democratic Party Tuesday afternoon.

Biden trailed former South Bend, Indiana, Mayor Pete Buttigieg and U.S. Sens. Bernie Sanders and Elizabeth Warren as of 6 p.m. Tuesday after the state party released the first batch of caucus results accounting for 62% of precincts. The results could change as more numbers are reported.

The Iowa Democratic Party reported Tuesday morning that a coding error in the smartphone app Democrats were using to report caucus results caused the app to only report partial data, which led to a delay in publicly posting the results.

Iowa caucuses: Live Democratic results and alignment tallies

More: Iowa Democratic Party chair apologizes for the delay in results reporting, which he says was 'unacceptable'

Throughout the day Tuesday, Biden campaign officials criticized how the results were reported Monday and urged Iowa Democrats to be cautious in releasing the caucus results.

"What we’re saying is that the Iowa Democratic party needs to be very judicious in checking, checking again and rechecking their data," Symone Sanders, a senior adviser to the campaign, said Tuesday morning.

"The reality is that there were considerable and serious failures in the process yesterday evening all throughout the evening at every single level."

A fundraising text message from the campaign just after 10 a.m. said "if anything, last night reinforced our campaign's anti-malarkey stance."

Dana Remus, general counsel for the Biden campaign, sent a letter Monday night to Iowa Democratic Party Chair Troy Price and Executive Director Kevin Geiken criticizing the party for "considerable flaws" in the caucus reporting system. The letter said the app and the party's system of calling in results by phone had both suffered "acute failures" statewide.

Price apologized in a news conference Tuesday afternoon, calling the delay "unacceptable."

The delay left the campaigns uncertain on Monday night of who had won the caucuses. Each candidate gave their preplanned speeches at their caucus night events before flying to New Hampshire.

Biden left Iowa around midnight Monday after addressing the crowd at his caucus night event at Drake University's Olmsted Center.

"From all indications, it’s going to be close," he told the crowd around 10:30 p.m. "We’re going to walk out of here with our share of delegates. We don’t know exactly what it is yet, but we feel good about where we are."

Biden didn't dwell on the lack of results for long. Instead, he jumped into a condensed version of his stump speech and spoke about the need to unite the country and rebuild the middle class.

Some of Biden's supporters, like Griffin Mensing, a senior at Drake University, expressed unease at the lack of results Monday night.

"I think it’s a tremendous problem on so many levels," said Mensing, 22. "And at the end of the day this is supposed to be a show of force, and Democrats are supposed to show that they’ve dotted their I's, crossed their T’s and all that. And it’s just not happening right now. But it is better to be safe than sorry and report correct results rather than have to go back and say you made a mistake."

Biden was feeling optimistic heading into the caucuses. In an interview with the Des Moines Register on Sunday, he expressed confidence in his Iowa organization but said the results would depend on who turned out to caucus.

"I feel good about the ground game … Iowa’s an unusual place, you know. It depends who turns up when, where and how. But we have a lot of people, we have a lot of headquarters and we think we can do it," he said.

He also said he views the first four early states — Iowa, New Hampshire, Nevada and South Carolina — as a group and said he doesn't believe he has to win Iowa in order to win the nomination.

"I think we have to end up in the top cluster of Iowa. I think we’ll win but we don’t have to win," he told the Register.

Biden barnstormed Iowa in a nine-day bus tour leading to Caucus Day, hoping to lock in support from late-deciding Iowans and encourage others to make phone calls or knock on doors on his behalf. His efforts were boosted by support from labor unions and endorsements from prominent Iowa Democrats.

And Biden has sought to elevate himself above his Democratic rivals by going directly after Trump in a preview of what a general election between the two could look like.

"Ladies and gentlemen, in November, America will have the chance to answer the question: Does the character of the president matter? Yes or no? There’s a lot of issues in this campaign, and I look forward to debating them with Donald Trump," Biden told a crowd Thursday in Waukee.

Stephen Gruber-Miller covers the Iowa Statehouse and politics for the Register. He can be reached by email at sgrubermil@registermedia.com or by phone at 515-284-8169. Follow him on Twitter at @sgrubermiller.

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