HARRISBURG, Pa. >> President Donald Trump and former Vice President Joe Biden are stumping in Pennsylvania today, the last day before Election Day, with counties reporting that they have received more than 2.4 million mail-in and absentee ballots in the premier presidential battleground state.

Trump is expected to headline a rally in Scranton, in northeastern Pennsylvania, Biden’s birthplace and an area of the state where Trump performed well in 2016.

Biden is in western Pennsylvania, kicking off a canvass in Beaver County with labor unions and attending one drive-in rally in Pittsburgh with African American community leaders and another with Lady Gaga.

Vice President Mike Pence and Biden’s running mate, U.S. Sen. Kamala Harris, of California, are also all in Pennsylvania today.

All told, voters in Pennsylvania requested more than 3.1 million mail-in or absent ballots, or more than 10 times the amount received in 2016′s election.

The deadline to return ballots is when polls close at 8 p.m. Tuesday. State officials are urging voters to hand in their ballots, instead of trusting the Postal Service to deliver them on time.

Ballots that arrive in the mail as late as 5 p.m. Friday are to be counted under a state court order.

However, that deadline is in doubt, since the state Republican Party is challenging that order before the U.S. Supreme Court and is asking the court to reset the deadline to 8 p.m. Tuesday.

The majority of mail-in ballots are being cast by Democrats, according to state data, and late-arriving ballots could take on enormous importance if Pennsylvania turns out to be the crucial state in the election and they are potentially decisive.