Record numbers of voters have already cast their ballots in the 2020 election cycle, whether by mail or in-person absentee.
The flood of early votes — which was widely anticipated amid the coronavirus pandemic — has raised concerns about how long it will take mail and election systems in key states to process and tally all the ballots being sent in.
In most states, ballot processing precedes ballot counting. Processing can involve steps such as verifying signatures or checking photocopies of identification documents, depending on the state. In some states, processing may include scanning ballots, but not tabulating them until counting can begin.
States that start processing votes earlier may be able to avoid ballot-counting backlog, which could delay final results for days after next Tuesday's election. But some states don't start processing votes until Election Day, including the all-important battlegrounds of Pennsylvania and Wisconsin.
There are political implications at play. President Donald Trump has loudly condemned the efforts of some state leaders to expand mail-in ballot access due to the pandemic, claiming without evidence that the new rules will cause widespread voter fraud. The Trump campaign has filed lawsuits in multiple states, including Pennsylvania and Nevada, related to their mail-in ballot practices.
Far more Democrats than Republicans have voted by mail so far, according to data from 19 states compiled by the U.S. Elections Project. Former Vice President Joe Biden, the Democratic nominee, is beating Trump in national polling averages.
The prospect of mail-in votes being added to states' totals well after Election Day could prompt objections from elected officials, possibly including Trump, if the changes are significant.
Here's when swing states will start counting their ballots, and other key data:
* At least seven Pennsylvania counties plan to hold off on processing or counting their mail ballots until the day after Election Day, NBC News reported Friday.