New York's polls closed nearly three weeks ago. But many candidates still don't know whether they've won -- because New York City is still counting ballots that arrived in the mail.
These votes would be an afterthought in most years. In fact, in New York, which is typically far more reliant on in-person voting, state law requires a weeklong delay before counting absentee ballots. But this year, amid widespread worries of COVID-19 spreading at polling places, the number of mail-in ballots is surging far faster than states' ability to count them.
Elections experts are increasingly convinced that this surge, and the nation's patchwork method of handling it, could lead to a constitutional crisis in November.
Professor Charles Stewart III, director of the MIT Election Data & Science Lab, said he's concerned the confusion could last for "a couple weeks, maybe longer."
The resulting acrimony, he said, "could make Florida in 2000 look like a garden party."
'They've never had to run an election like this'
Every state processes ballots that arrive in the mail, but the number can vary widely. In Oregon and Colorado, elections are conducted almost entirely by mail. But in many others, the absentee ballots are reserved for voters who can't otherwise get to a polling place -- a number usually too small to swing an election.
But that's changed because of the pandemic.
"In Manhattan in 2016, there were approximately 7,000 presidential primary absentee voters," said Sarah Steiner, a former chair of the New York City Bar's Election Law Committee, who is now an election law attorney. "And you had Hillary and Bernie. That was a competitive primary."
This year, the number of absentee primary votes in Manhattan rose past 121,000.
In many cases, states have actively promoted mail-in ballots, hoping to mitigate potential viral outbreaks at polling places. For the first time, Nevada sent a primary ballot to every active registered voter, a system California plans to adopt in November. Other states, including Georgia, sent forms with which voters could request an absentee ballot.
In 2016, a quarter of ballots cast in the general were absentee or mail-in ballots. This year, University of Florida political science professor Michael McDonald expects that share to double -- whether counties are ready or not.
"When we called up [a county in] Alabama, for example," he said, "you could hear him open up a filing drawer, getting a manila envelope, counting, 'I got one, two, three, four, five, six mail ballots.' They've never had to run an election like this. And we still haven't seen some of these states run elections under COVID."
Even in states that have conducted primaries, and even with federal aid, the volume of mail ballots has led to some of those elections being labeled disasters.
'What a mess'
On June 9, around Atlanta, many voters who couldn't stand on their feet for three hours gave up and went home. Others brought folding chairs.
"What a mess," said Marilyn Marks, executive director of the Coalition for Good Governance, a group that advocates for election transparency. "If you had asked me before June 9, I would have told you, 'I'm not worried about mail-in ballots.'"
That changed, she said, when she saw lines spilling out of Georgia polling places and into the streets.
The long wait times have been chalked up to poll workers refusing to show up because of COVID-19, delayed poll openings and issues with voting machines -- all true, but also compounded by the huge number of voters who applied for absentee ballots and never received them, Marks said.
"There were probably 40,000 to 50,000 voters who requested an absentee ballot who never received it," says Georgia House Minority Leader Bob Trammell. Those voters, largely concentrated in key counties, began arriving in person at the polls.
Poll workers then had to make a call to verify voters never received one.
"And then they had to verify their name on a list. It's a drag on the system," Trammell said.
Many voters simply gave up. But, experts added, the chaos at the polls may pale in comparison to what's about to happen in elections offices.
'Taking a 1-hour handwriting seminar at the Holiday Inn by the airport does not make you a handwriting expert'
The task of counting absentee ballots is arduous and time consuming.
"When an absentee ballot comes back to the board of elections, the board has to sort the ballots into assembly districts," said Steiner, the New York City elections lawyer. "They have to verify that it was mailed by a certain time. Then they check the outer envelope, make sure it's intact. They open the envelope, clip the outer envelope to the inner envelope. Then they check the signature and date. And then they have to check all of this against the voter rolls to make sure the person didn't vote in person."
That's difficult enough under the best of circumstances. But this year, the people and machines charged with processing the crush of paperwork are already struggling -- some New York voters, in one case, said they didn't receive return envelopes.
Battleground states will face even more pressure in November.
"We're always concerned with the actual counting of ballots," said Micah Kubic, executive director of the American Civil Liberties Union of Florida.
In normal times, he said, a pileup of absentee ballots can lead to harried elections officials accepting -- or rejecting -- ballots without proper consideration.
"The thing i'm very nervous about is the signature-match rule," Kubic said, in which the signature on an absentee envelope is compared with the signature made by a voter when registering. "We're talking about signatures that might have been put on a registration form 30 years ago. Taking a one-hour handwriting seminar at the Holiday Inn by the airport does not make you a handwriting expert."
After accepted ballots make their way back to elections offices, city officials still need to find space count them.
"For a really large place like NYC, they're going to need commercial-grade extracting machines to deal with all these ballots," said Stewart of MIT. "These things are big and expensive. It's like buying a fire truck."
As part of the CARES Act, Congress allocated $400 million to help states administer elections, but much of that money was burned on primaries, and buying new machinery for a temporary pandemic is politically unpalatable in many states.
President Donald Trump has decried expanded access to mail-in ballots, citing baseless claims of widespread fraud. Experts said the real problem isn't fraudulent voting, but whether loads of legitimate ballots will overwhelm states and lead to an extended, chaotic counting process.
'Our worst-case scenario'
On a general election night, Americans are accustomed to knowing who's won the presidency relatively quickly. A candidate declaring victory before the results are clear could result in electoral mayhem.
"There's an election administrator's prayer -- that the election is not close," said Professor Michael McDonald of the University of Florida. "I think that's what we all need to pray for."
If it's not a blowout, he said, there is a real possibility of a vote tally that could hinge on absentee votes. And while experts have said mail-in ballots don't favor either party, Trump claiming that they favor Democrats could be a self-fulfilling prophecy.
"There's this thing called the blue shift," McDonald said, "in which the longer counting goes, the more Democratic votes come in."
Groups that traditionally lean Democrat, like young people, are more likely to send in absentee ballots closer to the deadline. Postal delays can contribute to the phenomenon as well.
"You think your ballot is just going to go across the city or even across the street. But that's not what actually happens," McDonald added. Since mail is processed in large cities, it's possible that a ballot dropped in a suburban Colorado mailbox can be sent to Albuquerque, New Mexico, for sorting, and then sent back to the same Colorado county's elections office.
In states where ballots need to simply be postmarked before Election Day, that means ballots may keep trickling in days later.
This November, that trickle could be a flood. And if Trump's unproven voter fraud allegations convince more Republicans not to request mail-in ballots, that "blue shift" could be even more pronounced.
"We could be in a situation where, since Republicans vote more on election day, it will look like Trump is winning," said McDonald. "And then the mail ballots come in and Biden wins."
In terms of public perception, he said, "That's our worst-case scenario."
Based on absentee voting numbers, past and present, the opposite scenario, in which Trump makes a comeback due to mail-in ballots, is much less likely.
Stewart said this raises other concerning prospects, including that traditionally "safe" states can't be immediately called on election night.
"Think about how the narrative gets played out on election night," he said. "You need a New York to be called, because what the nation is looking for is, 'Has someone gotten past the electoral college threshold?'"
A once-in-a-lifetime surge of absentee ballots could make analysts even less likely to call states early. And if vote counting goes beyond a couple days, Stewart said, darker scenarios begin to unfold.
"The nightmare scenario [is] a campaign to interfere with the counting," he said. "That's when you get not just the tweets you'd expect from the president and his supporters, but it could embolden local supporters or officials to act on those tweets -- to enact incendiary proposals, like a Republican state legislature saying, 'We can't trust the ballot-counting process, so we're just going to appoint the electors ourselves.'"
'Hopefully they'll take lessons from the primary'
Experts said the most important solutions may already have presented themselves.
"Hopefully they'll take the lessons from the primary, and apply them to the general," said Trammell of Georgia. "At the minimum, I'd say, they should start processing [absentee ballots] as soon as they start receiving them." He also suggested more ballot drop boxes, in which absentee ballots are picked up by elections officials, not the U.S. Postal Service.
Voting rights advocates also are calling for more funding for states, county election boards and even the Postal Service itself.
But Stewart said that's unlikely, considering the usual lack of action from Congress in an election year.
"States need to step forward -- or private philanthropy," he said, noting that the nonprofit Center for Tech and Civic Life recently donated $6.3 million to Wisconsin's five largest cities to help with upcoming elections.
Still, he said, there are states, like Kentucky, who despite complaints over lines and rejected absentee ballots, have managed to tabulate votes more quickly. At this moment, he says he's betting on states implementing proper processes -- or a landslide that mitigates the coming controversies.
In the meantime, the counting continues in New York City, leaving Steiner scurrying between offices.
"We're still worrying about these races," she said. "We don't know who won! We can't worry about November yet."
ABC News' Ben Siegel contributed to this report.