Trump will win Florida & North Carolina. Biden will win Wisconsin & Michigan (and maybe Arizona), meaning it all comes down to Pennsylvania.
In about two weeks time, they finish counting in PA and declare Biden the winner by 1000 votes. Trump goes to court, saying that the recent changes to PA voting were unlawful.
By early January, it ends up in the Supreme Court, who find in favor of Trump by a 5-4 margin, with ACB being the deciding vote.
Democrats bring new meaning to the term apoplectic, the 2nd US Civil War ensues, and the union breaks into two........
{and yes, I'm kind of joking......but sadly it's not an impossible scenario.........]