After voters in Pennsylvania, Georgia and Nevada went to the polls this month, some races hung in the balance for days as election officials waded through thousands of absentee ballots.

On Tuesday, a similar scenario is expected to play out in Kentucky and New York, where officials have already announced that some results will not be available for as long as a week.

In all five states, officials have contended with an avalanche of mail ballots as voters seek to avoid exposure to the novel coronavirus. It was a fresh illustration of how the pandemic is transforming the way elections are conducted in the United States.

It is also a stark preview of what’s coming on Nov. 3 — or, more accurately, what may not be coming: an election night result in the race for the White House.

If voters remain reluctant to cast ballots in person, November is likely to bring an even more massive wave of voting by mail than what has swept across the country during primary season. That, in turn, means that a close race between President Trump and former vice president Joe Biden, the presumptive Democratic nominee, in a pivotal state could take days, even weeks, to resolve, election officials across the country are warning.

Barring a landslide for either candidate, that scenario could invite an unprecedented test of the country’s faith in its elections: an extended period without a declared winner. Amid that uncertainty, few expect Trump, who has said repeatedly that he thinks mail voting could cost him the election, to soothe voter anxieties.

On Monday, the president fired off tweets making unfounded assertions that voting by mail will cause massive fraud and allow foreign countries to manipulate the vote, echoing claims by his attorney general, William P. Barr.

“Because of MAIL-IN BALLOTS, 2020 will be the most RIGGED Election in our nations history — unless this stupidity is ended,” Trump tweeted Monday morning. In a separate tweet, he claimed that “MILLIONS OF MAIL-IN BALLOTS WILL BE PRINTED BY FOREIGN COUNTRIES, AND OTHERS. IT WILL BE THE SCANDAL OF OUR TIMES!”

There is no evidence that such wide-scale fraud is possible, and election officials across the country have disputed Trump’s and Barr’s claims. Both Trump and Barr have voted by mail in past elections.

A volley of warring lawsuits by the national parties could add to the tense environment. Already, party lawyers are battling in court fights across the country to shape voting rules that will govern the election.

The situation could plunge the country into an electoral crisis not seen since the acrimonious recount between Democrat Al Gore and Republican George W. Bush 20 years ago, when the then-vice president did not concede until a Supreme Court ruling 35 days after the election, historians said. It was the longest Americans had ever waited in modern times to know who their next president would be.

A long vote count “is going to automatically create mayhem about a ‘rigged’ election,” said presidential historian Douglas Brinkley, quoting Trump’s oft-repeated accusation. “We’d be better off if Biden or Trump won by a substantial margin. If someone decisively wins, people will be content with the result.”

Chaotic primaries

The evidence that Nov. 3 may not resemble past presidential elections has accrued with each passing primary. First came Wisconsin on April 7, when officials processed a record number of absentee ballots — nearly 1.1 million votes. The U.S. Supreme Court had ordered officials to accept all mail ballots postmarked by Election Day and received six days later, delaying the release of results until the following Monday.

Then came Pennsylvania, and Georgia and Nevada after that — all states that saw record absentee voting, with about 3 million mail ballots cast in all.

In Georgia and Nevada, voters stood in hours-long lines past midnight, contributing to delayed tallies. In Georgia, still more delays ensued after difficulty with new voting machines forced many voters to fill out provisional ballots on paper.

Last Tuesday, a full week after the Georgia primary, election workers in Gwinnett County, a suburb of Atlanta, sat at tables spread out across the Rhodes Jordan Park community gym, piles of ballots still in front of them for processing. Gwinnett processed 85,000 mailed ballots in this year’s primaries — compared with a normal count of 18,000, according to county spokesman Joe Sorenson. The county finished on Friday — 10 days after polls had closed.

“Given the complexity of the task, that’s pretty good, to be honest,” Sorenson said.

Pennsylvania processed 1.5 million mail ballots this month, compared with 84,000 in its 2016 primary. In Nevada, this year’s number was 483,788, compared with about 25,000 in 2016.

In Kentucky, nearly 1 million voters had requested mail ballots as of last week, vastly more than the roughly 50,000 people who usually vote absentee. In New York, roughly 10 times the number of ballots mailed four years ago have been requested for Tuesday’s primary.

Other forces beyond the sheer volume of mail ballots have contributed to how long the counts have taken this spring. Some states don’t allow the processing of ballots to begin until in-person polls have closed on Election Day, a rule that hasn’t delayed outcomes in past elections, when fewer people have voted by mail.

This year, however, it’s a debilitating handicap, Pennsylvania Secretary of State Kathy Boockvar (D) said. She persuaded the state legislature to allow officials to begin processing mail ballots the morning of in-person voting for the June 2 primary.

It still wasn’t enough for a process that includes opening envelopes, verifying voters’ identities and scanning ballots into machines. “Thirteen hours doesn’t do it,” she said.

Pennsylvania did not finish tallying absentee ballots until 10 days after the primary.

Michigan and Wisconsin also prohibit election officials from processing mail ballots until Election Day. Together, the three competitive battleground states pushed Trump over the top in 2016 with a total margin of less than 90,000 votes.

Such rules virtually guarantee that results won’t be available on the night of the election — and point to the need, election officials say, for the public to shift its expectations.

“We would all like to know early,” said Ohio Secretary of State Frank LaRose (R). “This is a voter education effort. When we rely on absentee voting, there will be ballots that continue to arrive days after the election.”

LaRose said he expects about a quarter of the state’s electorate, or about 1.7 million voters, to cast ballots by mail this fall. In 2016, about 1.2 million did so.

“When you receive that volume, that avalanche of ballots, there’s some logistics that people underestimate,” he said.

The process is faster in the handful of states that have nearly universal mail voting, including Colorado. There, election officials are permitted to process ballots as they arrive — scanning them into high-capacity machines and quickly totaling results from scanners once polls have closed on election night.

“It’s really easy to get 60 or 70 percent of your ballots done before election night,” said Judd Choate, the state’s top elections officer, “but not if you have limitations on what ballots you can process or how you can process them.”

Another force at work this year: scarce resources. City and county election offices have struggled to retain poll workers amid the threat of the virus; in Kentucky’s Tuesday primary, worker shortages have reduced the number of planned polling places across the state to 200, down from 3,700 in a typical election year.

These shortages have bled into the work crunch that comes after election night, as well.

Preparing for November

Election officials are pleading with state lawmakers to adjust the rules to accommodate the crush of mail ballots they expect in the fall — an effort complicated by the president’s repeated attacks on the process.

In Pennsylvania, Boockvar expects to obtain legislative permission once again to start processing ballots before election night in November — although, this time, she said she will seek even more time than the 13 extra hours allowed in the primary.

In Michigan, however, Secretary of State Jocelyn Benson (D) so far has not been able to persuade her state’s Republican legislature to pass legislation allowing scanning to begin ahead of time. The president’s denunciations of mail voting make it harder to prepare for November, Benson said.

“There is tremendous need to adapt other laws to allow the election system as a whole to continue to operate smoothly,” she said in a statement.

Preparations that states are able to make now to prepare for the flood of mail ballots will shape how quickly Americans will learn who has won the presidential contest this fall.

Presidential elections are almost always called before counting is complete. Many news outlets, including The Washington Post, follow the predictions of the Associated Press, the wire service with a long track record of combining reported results with exit polling data to announce state-by-state results.

The surge in mail balloting this year has complicated those calls. In Georgia, the AP incorrectly declared runoffs in two Democratic House primaries where late returns of absentee ballots shifted the results.

David Scott, an AP deputy managing editor, said the races were called too early but said the organization takes into account the different ways that votes are cast.

The possibility that the winner of the White House race will not immediately be known will test both the candidates and the public’s tolerance for uncertainty. It is not unusual for campaigns to use early results to spin public opinion about the outcome. But during the Florida recount in 2000, neither Bush nor Gore ever threatened to not accept the ultimate outcome.

On Dec. 13, 2000, after a Supreme Court decision went for Bush, Gore gave a full-throated nod to his rival.

“What remains of partisan rancor must now be put aside, and may God bless his stewardship of this country,” Gore said of Bush.

Many critics doubt Trump will show such restraint. He has repeatedly demonstrated a willingness to cast doubt on election results without evidence of voting irregularities, such as when he claimed that millions of undocumented people voted illegally in the 2016 White House race.

In 2018, Trump questioned House Democrats’ sweep to power in part with some close victories in California; he accused Democrats — without evidence — of fraudulently stuffing ballot boxes. Mail balloting would make such fraud even easier, he said.

“We had seven elections for Congress and they were, like, tied, and they lost every one of them because they came and they dropped a whole pile of ballots on the table,” the president said in May. “But you don’t think they rip them out of mailboxes?”

For his part, Biden has recently escalated his rhetoric around voting rights and warned that Trump might not accept the results in November.

“This president is going to try to steal this election,” Biden said in an interview on “The Daily Show with Trevor Noah” this month. The presumptive Democratic presidential nominee said “my single greatest concern” is ensuring that the voting process is fair.

Tim Murtaugh, the communications director for the Trump campaign, dismissed Biden’s comments as “just another brainless conspiracy theory from Joe Biden as he continues to try to undermine confidence in our elections.”

“President Trump has been clear that he will accept the results of the 2020 election,” Murtaugh added.

Trump also shrugged off the accusation.

“Certainly if I don’t win, I don’t win. I mean, you know, go on and do other things,” Trump told Fox News this month.

Brinkley, the presidential historian, said the scenario he can imagine in which the country accepts the result widely is if it’s a “really obvious, deep loss” — for either candidate.

“People used to appreciate character, but we’re not in that era right now,” Brinkley said. “This is a battle for the heart and soul of the United States. Neither side is going to lay down their arms very easily.”

David Weigel, Matt Viser and Dan Balz in Washington and Jon Irwin in Lawrenceville, Ga., contributed to this report.