A coalition of election integrity groups urged the Supreme Court to uphold a lower court ruling that mail-in ballots must be received by Election Day, arguing federal law setting a single Election Day requires all ballots to be in election officials’ hands by the close of polls.
The groups, including the Honest Elections Project and the Center for Election Confidence, filed an amicus brief Tuesday backing the Republican National Committee challenge to Mississippi’s postmark deadline. The case, Watson v. Republican National Committee, could determine whether postmark-based deadlines in 14 states remain valid ahead of the 2026 midterms.
The brief also included the American Legislative Exchange Council and Restoring Integrity and Trust in Elections. The coalition cited Foster v. Love, arguing the “final act of selection” must occur on Election Day and that mail ballots received after that day are invalid.
Fourteen states and Washington, D.C., currently count ballots received after Election Day if postmarked on time. A ruling upholding the 5th Circuit could invalidate those rules and require ballots to be received by polls’ close. Since 2024, Kansas, Ohio, Utah, and North Dakota have moved to enforce receipt by Election Day.
Oral arguments are scheduled for March 23, with a decision expected by summer.
