President Trump has been arguing for a while that mail-in voting is vulnerable to fraud, and he pushed a new theme on that front in not-so-subtle terms Monday. In an all-caps tweet, he warned: "RIGGED 2020 ELECTION: MILLIONS OF MAIL-IN BALLOTS WILL BE PRINTED BY FOREIGN COUNTRIES, AND OTHERS. IT WILL BE THE SCANDAL OF OUR TIMES!" Before that, he tweeted a link to a Breitbart News story in which Attorney General William Barr expresses a similar sentiment. "It absolutely opens the floodgates to fraud," Barr said of mail-in voting during a Sunday interview on Fox News. "A foreign country could print up tens of thousands of counterfeit ballots, and (it would) be very hard for us to detect which was the right and which was the wrong ballot."
The coronavirus has led to calls for greater access to mail-in ballots for voters, but the White House opposes the move. "You get thousands and thousands of people sitting in somebody’s living room, signing ballots all over the place," Trump said in April, per the Hill. When reporters asked for evidence, he responded, "I think there's a lot of evidence, but we'll provide you with some, OK?" AFP reports that the political impact of mail-in voting is unclear, citing a new Stanford study that while the practice seems to increase overall voting, it "does not appear to increase either party's vote share." (In May, Twitter slapped fact-check warnings on Trump tweets about mail-in voting fraud.)