The claim
"I've been talking about mail-in voting for a long time. It's really destroyed our system. It's a corrupt system and it makes people corrupt."
Rating
There is no evidence the system is corrupt. Electoral fraud is very rare in the United States - the rate is less than 0.0009%, according to a 2017 study by the Brennan Center for Justice. There's no evidence to suggest it's been a major issue at this election either.
Reviewed by BBC Reality Check ↗ ·
Original fact check ↗