More recently, the 2020 Democratic primaries should serve as a cautionary tale. About six weeks after New York’s congressional primaries, winners were not declared in two closely watched House races until Tuesday. That’s thanks to complications in counting the surge of more than 400,000 mail-in ballots, of which state officials have already invalidated 84,000. In California, election officials rejected more than 100,000 mail-in ballots in the state’s March presidential primary. To put these numbers in perspective, Trump won the White House in 2016 thanks to roughly 80,000 votes in Michigan, Pennsylvania and Wisconsin combined. In Pennsylvania alone, mail ballot problems kept about 92,000 people from voting in a primary in a state that Trump won by just 44,000 votes four years ago. In Florida, about 18,500 mail-in ballots were not counted, and in Nevada, about 6,700 were rejected. In a close race, such failures could easily call the results into question.

None of these problems were because of fraud. They were because of mistakes by voters, postal problems or the inability to handle the massive surge in ballots that overwhelmed electoral systems not equipped to handle them. If election officials had this much trouble handing mail-in ballots during low-turnout primaries, imagine what will happen in the general election. Put aside the ability of election officials to process the results. Does anyone believe that the US Postal Service is ready to handle a sudden deluge of tens of millions of ballots right before Election Day? Millions of ballots are inevitably going to be delayed, be misdirected or arrive without postmarks. And many will be invalidated because voters made mistakes filling them out and could not ask election workers for help marking the ballots correctly.

If mail-in voting is permitted on an unprecedented scale, millions of votes will be rejected and the election could be thrown the election into chaos.