In theory ballots must be postmarked by election day.

But as we know from Comrade Stalin, "it's not who votes, it's who counts the votes."

The extra time allows them to figure out how many votes they need to steal. Election workers who happily generated fraudulent ballots in back rooms in prior elections aren't going to have any trouble here.

That said, if Trump's margin of victory is sufficient, and an army of attorneys are present in the states where it matters, they won't be able to get there.