TORONTO -- As record numbers of Americans request mail-in ballots to vote during COVID-19, it’s increasingly likely that the next U.S. president won’t be named on Nov. 3 as key battleground states count every last ballot.

But whether U.S. President Donald Trump accepts the results of what is shaping up to be an election dominated by mail-in voting remains uncertain.

Trump railed against mail-in voting at the first presidential debate on Tuesday night as he tried to cast doubt on the electoral process, specifically criticizing states that automatically mail ballots to every voter.

“This is going to be a fraud like you’ve never seen,” Trump said. “We might not know for months because these ballots are going to be all over.”

Trump also said he could turn to the U.S. Supreme Court to decide the winner of the election. The president is working to nominate conservative judge Amy Coney Barrett before the election, an appointment that would give the court a 6-3 majority for the conservative justices.

“I think I’m counting on them to look at the ballots, definitely. I hope we don’t need them in terms of the election itself,” Trump said.

Democratic candidate Joe Biden vowed to accept the results of the election, should he win or lose, and said Trump will have no choice but to accept them as well.

“I will accept it, and he will too. You know why? Once the winner is declared after all the votes are counted, that will be the end of it,” he said.

Biden also pushed back on Trump’s unfounded claim that mail-in voting is somehow less reliable, saying, “No one has established at all there is fraud related to mail-in ballots.”

Mail-in voting has been part of American elections for decades, and Trump himself has voted by mail in Florida despite simultaneously criticizing the process.

Amid the pandemic, mail-in voting has become an increasingly popular option for voters looking to cast their ballots without having to wait in long lines on Nov. 3. In Pennsylvania, a key battleground state this election that Trump narrowly won in 2016, more than a quarter of voters have requested absentee ballots. Requests for absentee ballots have already surpassed 2016 requests in other key states including Florida, Ohio, Wisconsin and Michigan.

Trump’s baseless claims about mail-in voting come as Democrats boast double and sometimes triple the number of voters who intend to vote by mail, according to state-level data compiled by the New York Times.

Back in 2016, Trump levelled similarly untrue claim that millions of fraudulent votes were cast to account for the fact that Hillary Clinton won the popular vote despite losing the electoral college.

There was widespread public outcry earlier this year after U.S. Postmaster General Louis DeJoy, a Republican fundraiser and ally to Trump, cut a series of services to the postal service that would slow down service, leading to significant delays in how mail is delivered that could impact the election. A series of judges have since struck down those changes, with one calling the move “a politically motivated attack.”

National polls consistently show Trump trailing Biden by a wide margin, with few fluctuations throughout the summer. On Tuesday, Biden maintained a six-point lead according to tracking by Real Clear Politics, and a seven-point lead according to FiveThirtyEight and the New York Times’ Upshot.

Post-debate polls, expected in the coming days, should provide a snapshot of how voters viewed the first face-to-face match-up of this election cycle. There are two more debates scheduled for later this fall, Oct. 15 and Oct. 22.

The vice-presidential debate between Kamala Harris and Mike Pence will take place next week, on Oct. 7.

Correction:

This story has been corrected to reflect the actual date of the third presidential debate on Oct. 22.