The most obvious and benign possible reason we might see delayed results on Election Day is what political scientist Charles Stewart and I call the “overtime count.” This term refers to ballots that are counted after election night, as the election officials canvass returns before finally certifying their results. Before 2002, when Congress passed legislation in response to the 2000 Florida recount, ballots tallied during the “overtime count” period represented a relatively small percentage of total ballots cast and usually could be ignored on election night without worrying about the accuracy of “calling” the election results that night. Of course, valid “overtime” ballots would continue to be counted, in order not to disenfranchise eligible voters, but the winners and losers virtually never would change, and so the public largely ignored the official declaration of results a week or two later.

But as a result of electoral reforms passed since 2000—well-intentioned responses to real problems that needed fixing—our electoral system now relies much more heavily on the “overtime count” phenomenon. For instance, provisional ballots—ballots whose validity is uncertain at the time they are cast—are now required not to be counted on election night. A review of these ballots is necessary during the canvassing of returns to determine their eligibility. (Although the federal requirement to use provisional ballots is nationwide, states vary in the degree to which they employ them.)

We have also seen a rapid rise in reliance on absentee or mail-in ballots. This trend accelerated after long lines began presenting problems in presidential elections, which prompted states to encourage more voters to use mail-in ballots. In the old days, it was necessary to have an “excuse” to vote absentee—a business trip, hospitalization or something else that physically prevented you from going to the polls on Election Day. Now, in many states, absentee voting is a common option, and the choice is the voter’s. Some states permit absentee ballots to be counted as long as they are postmarked by or on Election Day; they can arrive at local election offices several days later and still be eligible for counting. Obviously, these absentee ballots cannot be part of election night returns, and as they grow in number, they increase the likelihood that close elections won’t be decided right away.

In the 2018 midterms, for the first time, the overtime count made a difference in nationally important races. In Arizona, it flipped the outcome in the Senate race in favor of Democrat Kyrsten Sinema. In Florida, the overtime count caused election night leads for Republican Senate and gubernatorial candidates to slip significantly during the canvassing of returns. Although the Republican candidates held on in both cases, they and their supporters grew nervous as they saw their leads diminishing. (Just as the overtime count is not yet well understood, the fact that it tends to work to the advantage of Democrats—a phenomenon now called “the blue shift,” based on some of my own research—is also perplexing to many, with some jumping too quickly to the conclusion that shenanigans are at work.)

The problem in Iowa’s 2020 caucuses was not caused by provisional or absentee ballots and, thus, is not technically an overtime count. But an event nonetheless occurred that prevented knowing the winner on election night. At least so far, officials have made clear that there were no improprieties or hacks. Instead, the results are taking longer than expected due to a glitch in an app that was developed to report precinct tallies, followed by phone lines getting overloaded once the app failed. It’s understandable that these unexpected delays would cause confusion, but all signs suggest that, thanks to paper records, the caucuses will still succeed in their fundamental purpose: accurately assigning delegates for the Democratic nominating process. It is unfair to label Iowa an apocalyptic failure just because of a delay.