Republicans seem convinced that absentee voting (mail-in voting) cost them the 2020 presidential election. They believe it increased the number of voters, and when more voters participate they don't do well.And because of that belief, Republican legislatures in many states are trying to pass a whole range of laws to suppress voting in the future -- including making it harder to vote by mail.
But their belief about mail-in voting (like their belief in widespread voter fraud) has no basis in fact.
Several scholars did a study and produced a report for the Stanford University Institute for Economic Policy Research. They found that mail-in voting did not help or hurt either of the two parties in the 2020 election. Here is the summary of that report:
The 2020 U.S. election saw high turnout, a huge increase in absentee voting, and brought unified Democratic control at the federal level — yet, contrary to conventional wisdom, these facts do not imply that vote-by-mail increased turnout or had partisan effects. Using nationwide data, we find that states newly implementing no-excuse absentee voting for 2020 did not see larger increases in turnout than states that did not. Focusing on a natural experiment in Texas, we find that 65-year-olds turned out at nearly the same rate as 64-year-olds, even though 65-year-olds voted absentee at much higher rates than 64-year-olds because they could do so without having to provide an excuse. Being old enough to vote no-excuse absentee did not substantially increase Democratic turnout relative to Republican turnout, as the increase in Democratic absentee voting was offset by decreases in Democratic in person voting. Together, the results suggest that no-excuse absentee voting mobilized relatively few voters and had at most a muted partisan effect despite the historic pandemic. Voter interest appears to be far more important in driving turnout.
