WaPo:

Republican officials and candidates in at least three battleground states are pushing to disqualify thousands of mail ballots after urging their own supporters to vote on Election Day, in what critics are calling a concerted attempt at partisan voter suppression.

In Pennsylvania, the state Supreme Court has agreed with the Republican National Committee that election officials should not count ballots on which the voter neglected to put a date on the outer envelope — even in cases when the ballots arrive before Election Day. Thousands of ballots have been set aside as a result, enough to swing a close race.

In Michigan, Kristina Karamo, the Republican nominee for secretary of state, sued the top election official in Detroit last month, seeking to toss absentee ballots not cast in person with an ID, even though that runs contrary to state requirements. When asked in a recent court hearing, Karamo’s lawyer declined to say why the suit targets Detroit, a heavily Democratic, majority-Black city, and not the entire state.

And in Wisconsin, Republicans won a court ruling that will prevent some mail ballots from being counted when the required witness address is not complete.