I remember the law required that the ballots be postmarked on or before election day, so the 'Rats contested every overseas ballot without a postmark - even those received before election day. I don't remember if that was laughed out of court or if those ballots did end up being disqualified.
My point is the dimrats tried to disqualify the overseas ballots then. If they collude with the USPS, there will be a whole lot of ballots “lost” that originate from republican leaning districts all across the country.