The Iowa caucuses did not go as planned.

The first-in-the-nation presidential vote that took place Monday, marred by technical difficulties that forced the Iowa Democratic Party to count votes by hand and delay the release of results, has produced data that in many cases are confounding.

The national party leader, Democratic National Committee Chair Tom Perez, called Thursday for the state to be immediately recanvassed — similar to an audit of results — but has so far been rebuffed by the state party.

With 100% of the precincts reporting data, the NBC News Decision Desk has not declared a winner. According to the results that have been reported, the race is tight between former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Bernie Sanders, I-Vt., who have both declared victory.

The closeness of the race has magnified the significance of even minor errors, as they could be enough to determine the winner. CNBC is referring to the winner as the candidate who receives the most state delegate equivalents, an Electoral College-like measure of support that does not indicate actual votes cast.

Buttigieg led Sanders on the measure by 26.2% to 26.1%, while Sanders received more votes, according to Iowa Democratic Party data.

The NBC News Decision Desk identified a number of the apparent problems with the election data in a report published on Thursday.

A common error, according to CNBC's analysis, is that in many precincts — possibly more than 80 — the number of votes counted in what's known as the "final alignment" was greater than the number in the "first alignment."

That discrepancy is theoretically impossible under caucus rules, which are determined by the state party. Under those rules, voters gather in the first alignment to express support for their candidates. Supporters of candidates who do not reach a minimum viability threshold, generally 15%, must reallocate their support in the "final alignment."

It is possible for the number of voters in the final alignment to decrease from the first alignment. For instance, there are cases in which a supporter of a nonviable candidate in the first alignment simply did not vote in the final alignment. But it is seemingly impossible for there to be an increase in voters for the final alignment.

CNBC provided its findings to the Iowa Democratic Party, which has not responded to a request for comment. The number of precincts in each county where this problem appeared is indicated in the map accompanying this article.

The IDP said in a statement on Friday that due to "delays in reporting and some inconsistencies in data" it issued new guidance to presidential campaigns. The party said it will allow them to submit documentary evidence of incorrect data by Saturday at 1 p.m. ET.

It also extended the deadline for campaigns to file a requests for a recanvass or recount from Friday to Monday at 1 p.m. ET.