Voters across the country may have to wait days to find out whether Vice President Kamala Harris or former President Donald Trump win Pennsylvania’s 19 electoral votes, election officials say.

But Pennsylvania is literally the key state to decide who wins the White House once Tuesday’s votes are counted.

“Please be patient as our counties work around the clock, doing so as quickly as they can and with integrity,” Pennsylvania Secretary of State Al Schmidt said during a televised interview last month.

Election officials cautioned that the delays are not a cause for concern, but rather the result of Pennsylvania law that limits when counties can begin counting what could be more than 2 million mail-in ballots.

Four years ago, there was a four-day wait for those results, when counties counted nearly 3 million mail-in ballots. Voters requested fewer mail-in ballots before this election, and officials’ experience gained from four years of handling mail-in ballots has raised the confidence level for a faster turnaround to complete the count this time.

But results will likely take days, rather than hours.

“If we still have 5% of ballots cast by midnight, clearly we’ll be waiting another day or two to call Pennsylvania,” said Jeff Greenburg, a former elections director in Mercer County who now serves as an adviser to the Election Committee. the Seventy. a nonpartisan, nonprofit election watchdog group based in Philadelphia.

“Patience is the key word. The elections do not end at 8:01 pm We have to wait for certification. It won’t be as extended a schedule as we had in 2020. I’m sure the counties are prepared and in a very different place than we were in 2020,” Greenburg said.

Under state law, Pennsylvania counties cannot begin processing mail-in votes until 7 a.m. on Election Day. For the past four years, counties have lobbied in vain for state lawmakers to change election laws to allow mail-in votes to be counted sooner.

State grants awarded in recent years to purchase new equipment and hire additional staff are expected to speed up the process.

In Allegheny County, where more than 250,000 mail-in ballots could be cast, officials said equipment is available to open up to 50,000 mail-in ballot envelopes per hour. All mail-in ballots are expected to be counted by 8 p.m., when the polls close.

In Westmoreland County, where it took more than 24 hours to count more than nearly 50,000 votes cast by mail in 2020, officials said adding equipment and expertise will speed up the process. Nearly 60,000 Westmoreland voters requested mail-in ballots this fall, and more than 44,000 had been returned as of Thursday.

Elections Office Director Greg McCloskey said the county hopes to count all mail-in ballots by 10 p.m. on Election Day.

Mail-in votes accounted for about half of the votes cast in 2020. It will be a smaller percentage of all votes cast this year, officials said.

Millions of Pennsylvanians are still expected to vote at the polls. There are 1,327 congressional districts in Allegheny County. Results downloaded to flash drives will be transported to the county’s election warehouse and uploaded to the county’s computer system.

Westmoreland County has 306 precincts and those votes will be taken to the Greensburg courthouse on flash drives, with the results posted on the county website throughout the night. Officials say they expect that day’s voting totals to be complete around midnight.

Polls are scheduled to close at 8 pm on Election Day, but votes may still be cast later in the evening. Polls will remain open until everyone in line, even after the official closing time, can cast their vote, officials said.

The possibility of a large number of provisional votes could also cause delays in declaring a winner. Voters whose eligibility is in question or those who requested mail-in ballots but opted to vote in person at the polls can cast provisional ballots on Election Day. Officials have seven days after the election to evaluate whether those votes can be counted.

About 100,000 provisional ballots were cast in 2020 in Pennsylvania, where the presidential race was decided by just over 80,000 votes.

State law also allows votes cast by foreign voters and military members to be counted if they arrive seven days after the election.

“We expect that thousands of provisional and overseas votes will need to be counted, and that could take another day or two,” Greenburg said.

Officials said they have confidence in the process.

“This is our Super Bowl and we can’t screw it up,” said Westmoreland County Commissioner Sean Kertes.