With Tuesday’s U.S. presidential election upon us, it is far from certain that either President Donald Trump or his Democratic rival, former Vice President Joe Biden, will emerge as the clear winner on election night.

While Biden is leading Trump by a cumulative average of 8 percentage points in national polling, the Democrat’s lead shrinks to just a few points in a number of battleground states crucial to determining the winner in America’s unique system of indirect presidential election.

This has raised the odds that the election results could be delayed until all the ballots are officially tallied and certified. To be sure, a winner could well be declared if either Trump or Biden comes out on top with a large margin of votes.

But if the results are too close to call in some states, the ballots there could be subject to a recount and potential legal challenges, a process that could take weeks, if not longer, to sort out.

“There's nothing magical about Election Day or election night in terms of the legal requirements of finding out who won,” said James Gardner, a law professor and election law expert at the University of Buffalo. “What you have to do is go through the complete electoral process and count all the votes. And (if) that takes a few days or more, then we just wait.”

Tom Spencer, a veteran Republican election lawyer and vice president of the Lawyers Defense Fund, agrees that the impending electoral contest won’t be over until all the ballots are counted.

“I think that experienced election lawyers know that results change predicated upon when the ballots come in,” said Spencer, who served as co-counsel for the George W. Bush presidential ticket during the 2000 vote recount in Florida.

Hundreds of lawsuits

For American voters, this has been a year of confusion as Republican and Democratic lawyers have filed hundreds of lawsuits over voting by mail and other rules during the pandemic, making this election cycle the most litigated in history.

With the looming possibility that the presidential election outcome could be decided in the courts rather than at the ballot box, both the Trump and Biden campaigns have enlisted high-powered lawyers who have already begun running through various post-election scenarios.

“We have been planning for any post-election litigation and recounts for well over a year and are extraordinarily well-positioned,” Justin Riemer, chief counsel for the Republican National Committee, said in a statement to VOA. “With the help of our national network of attorneys, the RNC has been beating the Democrats in court for the last several months and that will continue should they attempt to sue their way to victory in November.”

A Biden campaign spokesperson did not respond to a request for comment. In an Oct. 9 tweet, Democratic lawyer Marc Elias wrote, “Republicans are spending $20 million to make voting more difficult in the middle of a pandemic that has cost over 200,000 lives.”

If any of the election results for president, members of Congress or state offices are close, losing candidates have two “remedies” available to them, Gardner said.

The first is a vote recount. Currently, 21 states allow for automatic recounts if the margin between the two opposing candidates is less than 1%, according to the National Conference of State Legislatures. In other states, a losing candidate can request a recount.

A recount “simply repeats, with greater care, the counting of ballots that were in the initial pool of ballots,” Gardner said.

If a recount does not change the results – they rarely do – the losing candidate can launch what is known as an election contest, essentially filing a legal challenge, Gardner said. This is the phase where the losing candidate can dispute the validity of ballots or practices used in counting the votes, triggering court battles that could take weeks and potentially end up before the U.S. Supreme Court.

State and federal courts all the way up to the Supreme Court have been busy for months dealing with more than 300 cases stemming from the primary and general election campaign – many of them having to do with mail-in voting and changes in procedures at polling places in response to the coronavirus pandemic.

This week, the Supreme Court allowed election officials in the battleground states of Pennsylvania and North Carolina to accept mail-in ballots that arrive three to six days after the election, respectively, after refusing to affirm Wisconsin's six-day ballot receipt extension.

“You could very well have a situation like we had in 2000 with ballot examination and counting teams going through thousands of ballots with observers from both parties looking over their shoulders,” Gardner said.

Late-arriving ballots

One potential area of post-election dispute will likely involve mail-in ballots that arrive after Election Day, said Sylvia Albert, director of voting and elections at Common Cause, a citizen advocacy organization.

As of Friday, there were still many millions of outstanding mail-in ballots. That means ballots that arrive after Election Day may not count in some states.

In Pennsylvania and Minnesota, two battleground states that accept mail-in ballots after Election Day, election officials will segregate late-arriving paper votes. How to dispose of those ballots could become the main issue in subsequent court cases. North Carolina, another key state, may do the same, Albert said.

“I think there will be an attempt to segregate those ballots to possibly have them thrown out,” Albert said.

Rejected mail-in ballots

Rejected mail-in ballots could become another focus of any post-election litigation.

During every U.S. presidential election, hundreds of thousands of mail-in ballots are discarded by election officials for a variety of reasons, from arriving after the deadline to missing a proper signature on the outer envelope.

But this year, because of the ramp-up in absentee voting, a lot more ballots face rejection, with minority and first-time voters disproportionately affected, according to experts. In North Carolina and Florida, respectively, more than 10,000 and 15,000 ballots face rejection.

Although voters in 30 states including Florida are given an opportunity to “cure” or correct problems with their ballots, voters in 20 other states are not afforded that opportunity. That means election officials can toss ballots without informing voters about the defects.

“I think there will be large disagreements and lots of wrangling over which of those ballots should count and which of the absentee voters should be able to correct any errors in their ballots,” Albert said.

Ballot drop boxes

Ballots placed in drop boxes across the country are another category of voting facing potential litigation.

While some states have long used free-standing boxes to collect ballots, this year 40 states will use them, according to the Stanford-MIT Healthy Elections Project.

The expanded use of drop boxes has become a major flashpoint in the debate over voting access during the pandemic and a focus of litigation in at least three states: Ohio, Pennsylvania and Texas.

While Democrats and voting rights advocates say drop boxes make it easier for voters to cast their ballots without exposing themselves to the virus, President Trump and Republicans have railed against them, describing them as a potential ballot security risks and trying to limit their number. In Texas, for example, Gov. Greg Abbott has limited the number of drop boxes to one per county.

While election officials have sought to reassure voters regarding the security of drop boxes, Republicans continue to argue that they pose problems. In Texas, litigation continues over whether ballots dropped in a collection box were secure enough to be counted, Albert, of Common Cause, said.

“I think there are going be arguments that drop boxes were not secure and therefore none of the ballots should count,” she said.