Problem is that once you start falling behind by 10-15% in a given state - depending on the rural/urban population ratio - it's hard to make up votes by cheating without running numbers that are 2-300% of the adult census population, much less eligible voters, much less registered voters.
Most rural, small town, and a good number of suburbanite counties are GOP with GOP election admins. Many Rat local election officials are honest and won't blatantly cheat pr at least won't risk their careers to do it.
So it falls to big urban centers like Detroit or Chicago to make up the votes, and the bigger the gap the more obvious it looks. There comes a point where you can't overcome that deficit.
If Biden really tanks, Indies are flipping to the GOP, GOP turnout is record breaking, and the Rat base just doesn't show up, the leadership will turn into cornered Rats, and who the heck knows what they'll do.