While each state runs its own process, those mail ballots can take longer to count. In some states, the ballots can be accepted several days after Election Day, as long as they are postmarked before polls closed. And while some states count the ballots as they come in, others — notably the critical battlegrounds of Michigan and Pennsylvania — have laws that forbid processing mail ballots until Election Day, guaranteeing the count will extend well past that night.
That doesn’t mean The Associated Press and other news organizations won’t call a winner. The AP regularly calls races before the official vote count is complete, using models based on partial results, past races and extensive polling.
But in particularly tight contests, the AP and other news organizations may hold off on declaring a winner. That could lead to a national roller coaster ride of shifting results.
In Arizona in 2018, for example, Republican Martha McSally was narrowly winning the initial tally of in-person votes and mail ballots that had arrived days before Election Day. More than a week later, after election officials were able to tally all the mail votes that arrived on Election Day, Democrat Kyrsten Sinema won the senatorial race by more than 2 percentage points. Arizona changed its procedures to try to speed up the vote count this year.
In Michigan and Pennsylvania, two states that helped hand Trump his 2016 victory, Democrats have pushed to relax the laws forbidding them from processing ballots before Election Day but faced GOP resistance.
In Michigan, GOP leaders had argued it would be improper to handle ballots before Election Day. But on Wednesday, the state’s GOP-controlled Senate signaled a shift, advancing a bill that would allow the processing of absentee ballots the day before Election Day. Benson said even if the bill passes, she expects a slow count in November.
“It’s certainly going to be a challenge,” Benson said.
In Pennsylvania, only 4.6% of the state’s voters voted either early or by mail in 2016. But now both parties are urging voters to send in mail ballots for next week’s primary elections, and officials are overwhelmed by absentee ballot requests.
Philadelphia says it won’t even begin to count mail ballots until after the end of primary day, June 2. Forrest K. Lehman, elections director in Lycoming County in central Pennsylvania, warned: “In terms of November, if they don’t let us start canvassing sooner than the day of the election, there’s no way anyone can responsibly call Pennsylvania on election night.”