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The Iowa Democratic Party on Tuesday released partial results from Monday night's caucuses after a lengthy delay caused by a "coding issue" with an app used to report the data.

The partial results, which come from each of the state's 99 counties but are inconclusive, show former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Bernie Sanders, I-Vt., at the front of the pack, although those positions may not hold when all the votes are eventually counted. The results also show former Vice President Joe Biden, the national front-runner, trailing the leaders. The data release comes after a storm of criticism from the campaigns about how the party conducted the caucus process.

Buttigieg and Sanders are likely to reach the 15 percent "viability threshold of support," allowing them to collect state delegate equivalents, according to NBC News.

Troy Price, the state party chairman, said the partial results represented 62 percent of the state's 99 counties.

Price called the issues surrounding Monday night's contest "unacceptable."

"The reporting of the results and circumstances surrounding the 2020 Iowa Democratic Party caucuses were unacceptable," he said. "As chair of the party, I apologize deeply for this."

Price said voters and campaigns should have faith in the reporting of the election data because it is backed up by a paper trail and documentation to verify the results. He also said the underlying raw numbers are secure.

"The bottom line is we hit a stumbling block, but the one thing I want you to know is this data is accurate," he said.

Price sidestepped renewed questions about whether Iowa should continue to go first in the nominating contests, as well as whether he should step down as chairman of the state party.

"The fact is that this is a conversation that happens every four years. There's no doubt that conversation will take place again," he said. "But right now, my focus is making sure that we get these results out. We're going to continue to do that."

Buttigieg was triumphant when he addressed supporters in New Hampshire following the announcement Tuesday.

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"We don't know all the numbers, but we do know this much: A campaign that started a year ago with four staff members, no name recognition, no money, just a big idea — a campaign that some said should have no business even making this attempt — has taken its place at the front of this race to replace the current president with a better vision for America," he said.

Jeff Weaver, a senior adviser to Sanders, said: "We want to thank the people of Iowa. We are gratified that in the partial data released so far it's clear that in the first and second round more people voted for Bernie than any other candidate in the field."

Caucusgoers convened at nearly 1,700 sites across Iowa on Monday to consolidate support behind their preferred candidates and to cajole others to back their favorites. The delay in vote reporting had frustrated the presidential candidates, who tried to rally their supporters despite the uncertainty as the election looks to the New Hampshire primary on Feb. 11.

The candidates who campaigned in Iowa included: Sanders; Buttigieg; Biden; Sen. Elizabeth Warren, D-Mass.; Sen. Amy Klobuchar, D-Minn.; entrepreneur Andrew Yang; and billionaire businessman Tom Steyer.

Live blog: Follow the latest news and results from the Iowa caucuses

By Tuesday morning, campaigns had shifted their attention toward New Hampshire while reassuring their supporters about the Iowa results.

Klobuchar told supporters in Concord, New Hampshire, on Tuesday that she and her team "feel really good about where we are, and we won so many precincts and delegates that I don't think people gave us a chance to win."

In Manchester, New Hampshire, Buttigieg also touched on Iowa, appearing to claim victory even before official results came in.

"The hope that propelled me into this campaign is vindicated every day," he said. "It was vindicated in a big way last night when we had a chance to quiet those questions of whether we belong in this effort in the first place."

Sanders criticized Buttigieg's early celebrations.

"I don't know how anybody declares victory before you have an official statement as to election results, so we're not declaring victory," Sanders said. "As of now, I think we're in quite good shape."

Sanders also told reporters while traveling to New Hampshire earlier Tuesday that he was frustrated with how the party handled the process.

"I think we should all be disappointed in the inability of the party to come up with timely results, but we are not casting aspirations on the votes that are being counted," he said. "There's no excuse for not having results last night, but that doesn't mean to say that the totals that come in will be inaccurate."

He added, "I think this is not a good night for democracy."

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Warren told supporters in New Hampshire on Tuesday that "we had a bumpy start to the Democratic process."

"Here's what we know," she said. "It's a tight three-way race at the top. We know that three of us will be dividing up most of the delegates in Iowa."

"I'm feeling good," she added.

But she also took Iowa Democratic officials to task.

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

Biden's campaign texted supporters Tuesday to raise money. The campaign's senior adviser, Symone Sanders, said in a series of tweets that the campaign exceeded expectations in Polk, Louisa and Linn counties.

Yang said in a tweet Tuesday morning that he saw a silver lining in the delay.

"This race is a muddled mess," he said. "That means the opportunity for us is growing because there isn't a clear front runner or even field."

He added, "New Hampshire will be more important than ever."