Mississippi has urged the U.S. Supreme Court to reverse a lower court ruling that struck down the state’s law permitting election officials to count mail-in ballots that arrive after Election Day, provided they are postmarked on or before that day.

In a brief filed Friday, Mississippi Secretary of State Michael Watson asked the justices to overturn an October 2024 decision by the Fifth Circuit, which held that federal election statutes require ballots not only to be cast, but also received, by Election Day. Mississippi argues that interpretation conflicts with the text of federal law, Supreme Court precedent, and longstanding historical practice.

The state contends that its statute does not alter the deadline for voting, but simply allows election officials to complete the counting process after Election Day for ballots that were timely cast. According to Mississippi, the Constitution and federal law leave states with broad authority to determine the manner of conducting elections.

“An ‘election’ is the conclusive choice of an officer,” Watson wrote. “The voters make the choice by casting — marking and submitting — their ballots. So the federal election-day statutes require only that the voters cast their ballots by election day.”

Mississippi warned that if the Fifth Circuit’s reasoning is allowed to stand, it could invalidate election laws that have existed for more than a century, including absentee voting systems and secret ballots. The state argued that Congress never intended to mandate in-person voting or require that ballots be physically received on Election Day.

The Fifth Circuit had concluded that historical practice at the time federal election statutes were enacted suggested ballots were typically received on Election Day. Mississippi countered that historical coincidence does not equate to a legal mandate, and that no statute, court ruling, or legislative record explicitly bars states from counting ballots received afterward.

Veterans advocacy group Vet Voice Foundation and the Mississippi Alliance for Retired Americans, which intervened in the case, filed a joint brief supporting Mississippi. They argued that affirming the Fifth Circuit would impose a sweeping change to election law that Congress itself has never enacted.

Mississippi noted that it is one of 14 states, along with Washington, D.C., and several U.S. territories, that count mail ballots arriving after Election Day if postmarked on time. Many additional states apply similar rules for military and overseas voters.

The case originated after the Republican National Committee, the Mississippi Republican Party, and the Libertarian Party of Mississippi challenged the state law in 2024. A federal district court initially upheld the statute, but the Fifth Circuit reversed, prompting Mississippi’s appeal to the Supreme Court.

Mississippi also pointed to Supreme Court precedent, including Foster v. Love, which described an election as “the act of choosing a person to fill an office,” emphasizing the voter’s act of casting a ballot rather than administrative receipt.

The state argued that recent expansions of absentee and mail voting do not violate federal election-day statutes, and that the appellate court failed to cite any authority showing Congress intended to prohibit post-Election Day ballot receipt.

Counsel for the parties did not immediately respond to requests for comment.

The case is Watson v. Republican National Committee et al., case number 24-1260, in the Supreme Court of the United States.