October Surprises
Trump, currently behind, can only win if an October surprise like 2016 happens.
There have been a couple opportunities: him contracting Covid-19, or the death of Justice Ginsburg and the nomination of Amy Coney Barrett to fill the Supreme Court vacancy. He tried to artificially create them, like Hunter Biden's emails or QAnon. However, as a one-dimensional candidate, he cannot change course from his losing strategy. With mail-in voting and a much smaller pool of undecided voters, an drastic upset will be difficult. However, a November surprise is still certainly possible, where the outcome is yet to be determined even after election day.