Here's a statement from Jimmy Carter, who led the 2005 bipartisan commission on voting that Barr and McEnany referred to, saying he urges an expansion of by-mail now and that the concerns of 15 years ago have in many ways been addressed
To push back on NV & MI absentee ballot application moves, the WH quoted a 2005 report Carter/Baker Commission report on potential fraud from absentee ballots. Worth noting: Carter is now calling for leaders "to expand vote-by-mail" during the pandemic