HARRISBURG, Pa. — Election boards in Pennsylvania's 67 counties may not invalidate mail-in ballots simply because they lack accurate, handwritten dates on their exterior return envelopes, a federal judge ruled Monday.

The decision by U.S. District Judge Susan Paradise Baxter, the latest in a long-running legal dispute over what is a small percentage of votes cast in the state, was issued more than two months after the state Supreme Court announced it also would consider the issue.

Baxter wrote that most counties did not try to argue that the exterior dates, which are not used to show whether a ballot was received in time, serve an important state interest in regulating elections. The Republican National Committee and one county, Berks, did argue the dates help combat voting fraud, Baxter wrote.

“Absent from the record, however, is any evidence demonstrating how this requirement furthers that purported interest," the judge wrote. The exterior envelope dating mandate violates the U.S. Constitution, she ruled, by impairing the right to vote under the First and Fourteenth amendments.

Jeff Bukowski, Berks County’s lawyer, said he will discuss a potential appeal with the county commissioners. Phone messages were left Monday with lawyers for the state and national Republican Party groups that intervened in the case and lost the ruling.

The voter and groups that sued, including Democratic campaign organizations and a teachers' union, called the exterior envelope dates “nothing more than a ‘compliance test’” to show how state voters “'can follow written instructions,'” Baxter said.

She ruled there is no state interest in requiring the signatures and noted that more than 10,000 votes statewide were invalidated as a result of the dating mandate in the 2022 election.

“Such disenfranchisement burdens the right to vote and there is no valid state interest to weigh this against,” Baxter wrote.

A decision by Baxter throwing out the envelope date mandate in a separate case was eventually reversed by the 3rd U.S. Circuit Court of Appeals, but it was decided on a different issue.

Lower courts have repeatedly deemed it unconstitutional or illegal to throw out such ballots. But higher courts — including the state Supreme Court most recently on Nov. 1 — have blocked those decisions from taking effect. New envelope designs have helped reduce the number of invalidated votes.