Bingo. It also requires one to possess a stamp. And the college kids who fill out the ballots screw them up by not signing or getting a witness signature
While it has been a good few weeks for Joe, they know they got caught flat footed in the GOTV game and other issues such as this. I believe that is why there is the current full court press to gaslight Trumps base, to even things out. As much as I can tell, early voting by Democrats is not any higher than normal, and not out distancing Republicans to say the least. Much of this is going to come to election day turnout.