(1) The left knows that Trump will win the election day physical vote by a landslide.
(2) The believe that the mail-in vote, which will be processed days after the election will favor Biden. (Mail-in fraud will almost guarantee this result.)
(3) Therefore, in order to seal the deal, the Dems will send in Antifa to disrupt the physical voting. This may occur the night before election day with general vandalism and fire-bombing of voting places. We may also see voting day intimidation of people at the polls.
Without the electoral votes being counted there is a Constitutional crises. And Trumps term ends.
Their are variants of this and similar approaches that the deep state has game plans for.
Ive said it for two years now. They will not let Trump have a second term.