The American Civil Liberties Union of Pennsylvania filed a petition on Friday to the US Supreme Court to determine if Pennsylvania’s requirement for voters to include a date on their mail ballot return envelopes violates federal law.

The case focuses on whether the state’s mandate requiring voters to manually write a date on their mail ballot return envelopes breaches the materiality clause of the 1964 Civil Rights Act. TheaAct protects voters from being denied their rights due to non-material errors on voting-related documents.

Shortly after the state’s municipal elections in November 2023, a federal district court judge determined that the date requirement was “entirely irrelevant” to assessing a voter’s eligibility, concluding that Pennsylvania’s mandate violated the relevant provision of the 1964 Civil Rights Act.

However, Republican organizations contested this decision, leading the US Court of Appeals for the Third Circuit to rule that the requirement did not breach the provision. The judges noted that the materiality clause pertains solely to the voter registration process and does not extend to regulations concerning the validity of ballots.

The petition to the US Supreme Court comes alongside a separate filing to the Pennsylvania Supreme Court. The ACLU filed that lawsuit on September 25 seeking to prevent county election boards from disqualifying mail ballots that lack a “correct” handwritten date on their return envelopes.

The ACLU and other advocates have argued that this requirement could disenfranchise over 10,000 eligible voters in the upcoming presidential election and that the requirement serves no meaningful purpose and disproportionately impacts older voters.