Why does it take more than one day for votes to be counted in Pennsylvania?
All eyes will be on Pennsylvania on Election Day and possibly for days to come because the commonwealth is a key battleground in the race for the White House.
The winner of the Keystone State's 19 electoral votes might not be clear on election night, though.
State law does not allow Pennsylvania election workers to start opening or counting mail-in ballots until 7 a.m. on Election Day, the same time polls open for in-person voting. More than two million voters in the state requested mail-in ballots for this election.
Many states allow workers to start preparing mail-in ballots ahead of Election Day, which means they could have votes tallied more quickly.
Four years ago, former President Donald Trump's "Stop the Steal" movement was born in Pennsylvania when the then-president spread misinformation about voter fraud. In reality, Trump's lead in Pennsylvania dwindled as its 67 counties worked around the clock to process millions of mail-in ballots. President Biden was ultimately named the projected winner of Pennsylvania in late morning on Saturday, Nov. 7. Trump won the state in 2016.
It's hard to say if the timing will be similar this year, though, experts told CBS News.
Just because results aren't available right away doesn't mean anything's gone wrong or any fraud is happening, experts and officials say.
"There is no evidence whatsoever that voter fraud takes place — in any way that is widespread at all," Al Schmidt, Pennsylvania's top elections official, told CBS News earlier this year.
Montgomery County Commissioner Neil Makhija said he expects the county will finish counting votes by late afternoon Wednesday.
Bucks County Commissioner Bob Harvie, chair of the county's Board of Elections, did not make a prediction but said counting the votes takes time.
"It's going to be probably next to impossible for us to be done on the night of the election, or even maybe early morning after the election," he said.
If a race is close, the final results could take even longer. Pennsylvania has an automatic recount if the margin in any statewide race is 0.5% of votes or less. The state also allows losing candidates to file a request for a machine recount if they pay for it. A refund may be available depending on the findings.
Officials in Philadelphia and the surrounding counties said they're prepared to count mail-in ballots on Election Day and to make sure the election is secure.