Other than all the times where fraud has been found. When has there ever been fraud. /s
Mail-in gave the Dems 50,000 more primary votes in one county here in PA (nearly the entire mail-in vote). The only way to prove that that county didn’t send in that many leftist votes is for every Trump voter to go to the polls. That’s the only way to make the fraud obvious to everyone.
People who vote by mail are letting the postal workers union decide what happens to their vote.