President Trump’s public disapproval of mail-in voting might come too late to make a difference for the 2020 election.

The six most important swing states for the Electoral College map — Pennsylvania, Michigan, Wisconsin, Arizona, Florida, and North Carolina — all allow voters to request mail-in or absentee ballots for any reason. Large percentages of voters in Florida and Arizona, where voters can opt to receive ballots by mail automatically, have voted absentee for the last decade.