Hans Von Spakovsky has written a critique of absentee voting for the Heritage Foundation. You can find it here.
Abstract: Trading the security, integrity, and shared experience of the in-person election process for all-mail elections is a bad idea for a number of reasons. An examination of voter fraud cases over the past two decades reveals that ballots requested and sent through the mail are vote thieves’ tool of choice. Despite claims that voting by mail will increase voter turnout, the evidence leads to the exact opposite conclusion. Such elections, while possi bly less expensive for election administrators, can be more expensive for candidates, thereby increasing the costs of campaigns for ordinary citizens who want to run for office. Mail elections put voters at the mercy of the postal service: If their ballots are delayed or misdirected, their votes will not count. Also, voters could be casting their ballots without the same access to timely information about candidates. Finally, elections conducted through the mail destroy the communal act of voting in a way that is damaging to America’s voting traditions and the inculcation of civic virtues.