Mail-in ballots in Pennsylvania without accurate handwritten dates on their exterior envelopes must still be counted if they are received in time, a judge ruled Tuesday, concluding that rejecting such ballots violates federal civil rights law.

The decision has implications for the 2024 presidential election in a key battleground state where Democrats have been far more likely to vote by mail than Republicans.

In the latest lawsuit filed over a 2019 state voting law, U.S. District Judge Susan Paradise Baxter ruled that county boards of election may no longer reject mail ballots that lack accurate, handwritten dates on their return envelopes. Baxter said the date — which is required by state law — is irrelevant in helping elections officials decide whether the ballot was received in time or whether the voter is qualified to cast a ballot.

The GOP has repeatedly fought in court to get such ballots thrown out, part of a campaign to invalidate mail-in ballots and mail-in voting in Pennsylvania after then-President Donald Trump baselessly claimed in 2020 that mail balloting was rife with fraud.

The judge, a Trump appointee, sided with several Pennsylvania groups represented by the American Civil Liberties Union, which argued that refusing to count such ballots “because of a trivial paperwork error” disenfranchises voters and violates provisions of the U.S. Civil Rights Act of 1964, which states that immaterial errors or omissions should not be used to prevent voting.

The suit was filed by state chapters of the NAACP, League of Women Voters, Common Cause, the Black Political Empowerment Project and other groups.

“Throwing out valid votes because of a minor paperwork error is undemocratic and illegal,” Ari Savitzky, senior staff attorney with the ACLU’s Voting Rights Project, said in a written statement Tuesday. “This ruling ensures that Pennsylvanians who vote by mail, including senior citizens and voters with disabilities, will not face disenfranchisement because of a trivial mistake in handwriting an irrelevant date on the outer return envelope.”

The Civil Rights Act of 1964 forbids states from denying the right to vote “because of an error or omission on any record or paper” if the error is irrelevant in determining whether the person is qualified to vote in the election.

In Pennsylvania’s case, elections officials do not use the date on the outer envelope to determine whether the vote should be counted, the judge said.

“The important date for casting the ballot is the date the ballot is received. Here, the date on the outside envelope was not used by any of the county boards to determine when a voter’s mail ballot was received in the November 2022 election,” Baxter wrote.

In that election, more than 7,600 mail ballots in 12 counties were tossed because the outer envelope lacked a date or had an incorrect date, according to the decision. Those counties were among the defendants in the suit.

The Pennsylvania Department of State under Democratic Gov. Josh Shapiro, which oversees elections statewide, said in a statement that it is reviewing the court’s decision, “but we are pleased with the result.”

The status of ballots without properly dated envelopes has been repeatedly litigated since the use of mail-in voting greatly expanded in Pennsylvania under a state law passed in 2019.

In November 2022, the state Supreme Court unanimously barred officials from counting such votes, directing county boards of elections to “segregate and preserve” those ballots. But the justices were split over whether making the envelope dates mandatory under state law would violate provisions of federal civil rights law — the issue at play in Tuesday’s federal court ruling.

The Department of State has said the state court decision to bar mail-in ballots without accurate handwritten dates resulted in otherwise valid votes being thrown out. The agency said more than 16,000 mail-in ballots in the 2022 midterm election were disqualified by county officials because they lacked secrecy envelopes or proper signatures or dates.

Democratic voters made up more than two-thirds of the total cancelled ballots.

The 3rd U.S. Circuit Court of Appeals ruled in May 2022 that the dates are not mandatory, but the U.S. Supreme Court then deemed that decision moot, prompting the lawsuit that was decided Tuesday.

National and state Republican committees argued the date requirement is useful in detecting fraud and that the materiality provision of the Civil Rights Act was inapplicable. An email message was sent to the GOP’s lawyers seeking comment on Tuesday’s decision.