Fact is that mail in voting has been banned in European countries and elections overturned because its much easier to cheat.
I would need more some statistical evidence. So far I have seen graphs pointing out how Biden's tally doesn't follow Benford’s Law.
https://principia-scientific.com/joe-bidens-votes-violate-be...
"Michigan County Clerk Admits Voting Software Glitch "Skewed" Results, Trump To Gain 6,000 Votes
https://thefederalistpapers.org/us/michigan-county-clerk-adm...
This is going to go in front of the Supreme Court. Twitter should not be trying to hide the fact that one of the parties claims fraud. A huge number of people voted for Trump. Let him make his case.
My Gut instinct is that it is suspicious that some democratic counties got 90% turnout.