The former South Bend, Indiana, mayor leads the Vermont senator by one-tenth of one percentage point in the all-important state delegate equivalent count. Massachusetts Sen. Elizabeth Warren , former Vice President Joe Biden and Minnesota Sen. Amy Klobuchar are trailing behind Buttigieg and Sanders.

But a CNN analysis shows that multiple counties have reported a different number of state delegate equivalents than they were supposed to have reported, even though all precincts in the county have been tallied. A similar problem appears in several precincts which awarded more state delegate equivalents than they were allotted by the Iowa Democratic Party.

Precinct-level data reveals multiple precincts where violations of the caucus rules may have occurred. In several precincts, the total vote reported in the final round of the popular vote exceeded the total vote in the first round, even though no one new should have been allowed into the room between the two rounds. And in some cases, a viable candidate lost support from the first round to the final round, even though supporters of viable candidates in the first round were supposed to be locked in to their first choice.

At satellite caucuses, the number of state delegate equivalents awarded per congressional district was calculated based on the turnout across all satellite caucuses within that district. The reported total state delegate equivalents appear to differ from the expected values based on the reported first round vote and the formulas announced by the Iowa Democratic Party.

Questions have also been raised about the methods the party used to assign state delegate equivalents to satellite caucus locations within each congressional district. Some individual precincts appear to have received more state delegate equivalents than they should have based on the rules for allocation.

Democratic National Committee Chair Tom Perez called for a recanvass of all results in Iowa on Thursday, as the state's Democratic Party continued to struggle to verify the data from Monday night's caucuses, which represented a significant step in the fallout from the chaos that followed the quadrennial event. In a recanvass, all the numbers released by the state party would be checked against the results that were recorded at caucus sites.

"Enough is enough," Perez tweeted. "In light of the problems that have emerged in the implementation of the delegate selection plan and in order to assure public confidence in the results, I am calling on the Iowa Democratic Party to immediately begin a recanvass."

Iowa Democratic Party Chair Troy Price released a statement responding to Perez, saying the party is prepared to conduct a recanvass "should any presidential campaign" request one.

"Should any presidential campaign in compliance with the Iowa Delegate Selection Plan request a recanvass, the IDP is prepared," he said. "In such a circumstance, the IDP will audit the paper records of report, as provided by the precinct chairs and signed by representatives of presidential campaigns. This is the official record of the Iowa Democratic caucus, and we are committed to ensuring the results accurately reflect the preference of Iowans."

The Democratic candidates have until 1 p.m. ET/12 p.m. CT on Friday to file a request for a recanvass or a recount.