On November 10, 2025, the U.S. Supreme Court announced that it will decide a critical legal question concerning the counting of mail-in ballots in federal elections: specifically, whether federal law prohibits states from counting absentee ballots that arrive after Election Day. This decision arises from an ongoing dispute over Mississippi’s procedures for counting late-arriving absentee ballots and has broader implications for numerous other states that permit mail-in ballots to be counted if they arrive after Election Day but were postmarked by or on that day.
The controversy centers on the interpretation of “Election Day” as defined by federal law versus the states’ authority to regulate their own election processes. Congress has established a uniform federal election day—the Tuesday following the first Monday in November—for choosing candidates for the House of Representatives, Senate, and presidency. However, in recent years, various states have enacted laws allowing mail-in ballots to be received and counted days after Election Day, provided they were postmarked by Election Day.
Mississippi’s law is a prime example of this approach. Initially enacted during the COVID-19 pandemic to facilitate safer voting, the state permits absentee ballots that are postmarked by Election Day to be accepted and counted if they arrive within five days after Election Day. This law was later made permanent. According to the National Conference of State Legislatures, sixteen states currently allow similar practices, which has raised questions about the uniformity of federal election laws and the scope of state authority.
The legal battle was initiated in January 2024 when the Republican National Committee, the Mississippi Republican Party, a voter, and a county election commissioner filed a lawsuit against Mississippi’s election officials. They claimed that Mississippi’s law conflicts with federal statutes that designate Election Day as the definitive day for federal elections. The plaintiffs argued that the state’s procedures violate their constitutional rights under the First and Fourteenth Amendments, contending that allowing ballots to be counted after Election Day effectively extends the voting period beyond what federal law permits. The Libertarian Party of Mississippi also joined the dispute.
A U.S. district court in Gulfport, Mississippi, initially ruled in favor of the state officials. The court held that Mississippi’s law does not conflict with federal election laws because federal statutes do not explicitly regulate the timing of mail-in ballot receipt and counting. The judge emphasized that states retain the constitutional authority to regulate “the time, place, and manner” of elections in the absence of specific federal rules. Importantly, the court found that no “final selection” of candidates occurs after Election Day under Mississippi’s law; rather, the ballots counted after Election Day were cast on or before Election Day, and the post-election counting process does not extend or alter the election itself.
However, the Republican plaintiffs appealed the decision to the U.S. Court of Appeals for the Fifth Circuit. A three-judge panel of that court unanimously reversed the district court’s ruling, siding with the Republicans. Judge Andrew Oldham, writing for the panel, declared that federal law requires ballots to be both cast and received by Election Day. He argued that the election remains ongoing while ballots are still being received, meaning that accepting ballots after Election Day extends the election period beyond what Congress intended. According to Oldham, the term “Election Day” means the day by which voters must complete all voting actions, including submission of ballots, to be counted. The panel concluded that Mississippi’s law was preempted by federal law and therefore invalid.
Mississippi officials requested a rehearing before the full Fifth Circuit, but the court declined. Subsequently, the state appealed to the Supreme Court, warning that if the Fifth Circuit’s decision stands, it could have destabilizing effects nationwide. The state contended that voters make their choice of a federal candidate when they mark and submit their ballots by Election Day, even if the physical ballots are received days later. They argued that counting votes is a separate administrative task that can lawfully occur after Election Day without extending or altering the election itself.
Mississippi further cautioned that the Fifth Circuit’s interpretation could force many states to eliminate their mail-in ballot grace periods, potentially disenfranchising voters and sparking widespread litigation. The state underscored the urgency of the Supreme Court’s ruling, noting that the 2026 midterm elections are less than 18 months away and that states need clear guidance on whether their post-Election Day ballot receipt laws comply with federal law or must be amended. The state highlighted the high stakes, emphasizing that ballots received after Election Day can influence