Undated mail-in ballots will not be counted in Pennsylvania, even if they arrive to election officials on time.

The legal question is whether “undated ballots” violate the Civil Rights Act of 1964, which says one’s right to vote cannot be denied for “an error or omission” that is “not material.” A three-judge panel in a U.S. Circuit Court of Appeals struck down a lower court ruling in favor of counting undated ballots.