People holding their breath to see how Pennsylvania votes in the 2020 presidential election might not want to wait up too late on election night.

While the unofficial and more immediately available results have accounted for the vast majority of votes cast in years past, a new law means a significant share of ballots might not be tallied until after Election Day, according to county elections officials. Races with razor-thin margins may be too close to call for days.

It’s an unintended consequence of changes meant to make voting more flexible and accessible, including by making absentee ballots available to everyone. Many of those mail-in ballots won’t be counted on election night — even in counties that used to include them in their initial results.

None of this changes the official, certified results that already come in long after the world knows who won. But being able to “call” a race in the hours after polls close has become an expectation for the public, with news organizations building sophisticated models for projecting winners based on unofficial results as they come in.

And Pennsylvania is a critical swing state in presidential elections. Donald Trump won the state in 2016 with just 44,292 more votes than Hillary Clinton, less than 1% of the more than 6.1 million votes cast. Along with similarly narrow victories in Michigan and Wisconsin, Pennsylvania was key in elevating Trump to the White House — and is again expected to be close.

“No county wants to be the reason we don’t know the leader of the free world on election night,” said Lee Soltysiak, Montgomery County’s chief operating officer and clerk of its election board. “And that’s the position, depending on the margin, we’re all likely to be in.”

In addition to many more absentee ballots likely than in the past, the new election law changes how they are processed.

“The election night numbers are going to be minus what we anticipate will be a fairly sizable number of ballots that have not yet been counted and will be counted later that week,” said Randall O. Wenger, the chief clerk of the elections board in Lancaster County. Absentee ballots there used to be counted on election night, but now that won’t happen until the day after.

“Your universe of uncounted ballots just blew up big time on election night,” said Forrest Lehman, elections director for Lycoming County, in central Pennsylvania.

Kathy Boockvar, Pennsylvania’s secretary of the commonwealth, whose Department of State oversees elections, pushed back on the idea that county election officials won’t be able to count absentee ballots right away. Counties need to adjust their staffing, purchase new equipment, and change some of their current procedures, she said, and then they’ll “have everything ready to go so literally when the clock ticks 8, they can start the canvass.”

There’s a period of time when “there’s not a lot going on” for elections officials, Boockvar said, after polls close and before the first results start coming in from polling places.

“There are lots of good procedures that have been developed over time in other places,” Boockvar said. “We are going to be sharing those. And I think as long as the counties plan for that extra staffing at 8 p.m. on Election Day, it’s going to be fine.”

But that would further strain county resources, officials said, as they are already struggling to implement other changes in the law, roll out new voting machines, and accommodate expected high turnout. And after a version of this story was published online, local officials pushed back on Boockvar’s comments, describing them as irresponsible in setting public expectations.

“There’s no possible way we would ever be able to do it on election night," said Sara May-Silfee, elections director for Monroe County, in northeast Pennsylvania. "I don’t even know why she thinks we would be able to do that. Obviously, she’s never worked in an election office on election night.”

Florence Kellett, elections director for Wyoming County, in northeast Pennsylvania, said: "They can take their ‘other states do it’ all they want, procedure’s procedure. I’m not changing it. ... I want a Porsche, I don’t see that happening, either.”

Philadelphia, the largest county in the state, will continue to hold off counting absentee ballots until after Election Day. The second-largest county, Allegheny, counted absentee ballots on election night in the past but might not be able to in the future.

Officials in Bucks County, a key suburban Philadelphia battleground, don’t expect to start counting absentee ballots that night. Elections director Tom Freitag told county commissioners at a meeting this week that his office likely wouldn’t be done counting “until a few days later.”

Bucks County Commissioner Gene DiGirolamo, a former state lawmaker who voted in favor of the new election measures last year, asked Freitag what that could mean in November.

“So if there’s an election that’s somewhat close, it’s really going to be up in the air until two, three days later,” DiGirolamo said.

“Yes, probably,” Freitag responded.

Westmoreland County, which used to count absentee ballots on election night, likely won’t do so anymore, either, elections director Beth Lechman said. Chester County also used to count them on election night, and officials there aren’t sure whether they will again. Northampton County does plan to count them on election night.

“We have no way of counting our mail-in/absentee ballots on election night,” said Jeff Greenburg, elections director for Mercer County, in Western Pennsylvania. “We will begin working on our absentees the following morning.”

All this means that it’s highly likely many, if not most, of the state’s absentee ballots will be missing from election night results, in counties both large and small, Democratic and Republican.

In the past, restrictions on absentee ballots meant only about 5% of votes were cast absentee. Now, any Pennsylvania voter can request a mail-in ballot without providing a justification. That’s generally good news for voters, elections officials said, but it significantly changes the election night calculus if suddenly three or four times as many absentee ballots are being cast.

While counties used to distribute absentee ballots to polling places, allowing them to be counted by poll workers on election night, the new law requires them to be counted by county officials in one central location. Even for a small county, that could mean thousands of votes being counted in one spot instead of being processed in small batches in multiple locations at the same time.

Lehigh County officials also don’t expect to start immediately counting absentee ballots. “I don’t know if I want to open that can of worms on election night, just because of how crazy it is,” said Timothy A. Benyo, chief clerk for the county elections board and chair of the Association of Eastern Pennsylvania County Election Personnel.

Boockvar noted the state is reimbursing counties for about 60% of the cost of election equipment and providing them guidance — “giving tremendous amounts of resources,” she said. County officials haven’t raised the issue of counting absentee ballots “as a major concern,” she said.

“I’d be really surprised if the huge majority of counties did not do counting that night,” Boockvar said. “And yes, we absolutely would urge the counties to do so.”

County elections officials are hoping to tamp down the expectations of people hungry for unofficial results.

“As long as our voters understand that this is what’s going to happen, and it may not be until Thursday or Friday … then they’ll be fine,” said Greenburg, of Mercer County.

Greenburg is buying two more ballot scanners to process mail-in ballots more quickly, at a cost of almost $100,000. Lehman said Lycoming County is buying a second scanner for about $21,000, Wenger said Lancaster County is buying another for $32,000, and Soltysiak said Montgomery County will buy three more for about $75,000.

But it won’t be fast enough for people used to having results immediately, Wenger said.

“As an elections administrator, the idea that election night numbers are woefully incomplete is not something that brings me any joy, because I know the hate emails I [already] get,” he said.

He’s already prepared for the public response if a winner takes days to call.

“I assure you,” Wenger said, “it’s not going to be positive.”