The Democratic presidential candidates were supposed to find out on the evening of Monday February 3 who had won the support of the first state Iowa.
But as caucuses met across the midwest state, results failed to materialise and many were left scratching their heads.
The party denied that its brand new system to collate votes crashed, and instead insisted the numbers were being double checked.
Candidates such as Bernie Sanders, Elizabeth Warren, Pete Buttigieg and Joe Biden were left in the dark and reports of “inconsistencies” in the nomination votes surfaced.
Why have the Iowa caucus results been delayed?
According to the Democratic Party, the delay in the result was due to “quality checks” on the results and new reporting rules.
The party has denied that an app used to send in the results of each caucus crashed, was hacked, or suffered an intrusion.
But the chair of the Des Moines County Democratic Party said the new software was faulty and that results had to be phoned through, and there were similar reports on Twitter and from other Chairs.
The central party added they had "found inconsistencies in the reporting of three sets of results".
“In addition to the tech systems being used to tabulate results, we are also using photos of results and a paper trail to validate that all results match and ensure that we have confidence and accuracy in the numbers we report,” a spokesperson added.
How does the voting system work?
The caucus system used in Iowa to choose a candidate was far from sophisticated in the first place.
Across the state of Iowa there are a total of 1,629 meetings - one in each precinct - usually held in sports halls or similar assembly centres.
At each one members of the Democratic Party congregate and discuss the candidates, policies and who they want to vote for.
The card-carriers then split and stand in groups under signs of who they want to be the presidential nominee.
People are free to discuss and lobby members of other groups to back their candidate while this process is ongoing.
When it has settled down a first count is taken, with a recorder noting down how many people are there in total, and how much support each candidate has received.
After the first round of voting, any candidate who fails to meet the threshold number of supporters gets knocked out and their backers can choose to move to one the remaining choices.
More lobbying and debating takes place before the final vote is totted up and each precinct reports to the central party how much support each candidate received.
With more than 1,500 results having to be reported in one night, it is no wonder that things get a little complicated.
How long has the app been used?
This was the first time the app to report results was used.
According to the New York Times, the app was only built in two months running up to the caucuses and had not been tested on a state-wide scale.
It was reportedly developed by a company called Shadow Inc.
Reports on social media suggested that Democratic Party chairs were having to spend hours on the phone on hold to the central office before they could report their precinct's results.
What happens next?
A result from the caucus was expected to be revealed on the evening of Monday February 3 in America.
But after hours of waiting and no results, the Democrats said in the middle of the night the result would be published on Tuesday February 4.
Candidates would typically use the result from Iowa to build momentum in the New Hampshire primary the week after.
But a number of the candidates declared a pseudo-victory despite not having official results and set off to continue their campaigns.
The fumbling of the vote will take some of the impact out of the result when it does come through, softening the winner's joy and easing the defeated's loss.
