Supreme Court Upholds Ballot Postmark Grace Period Laws

On June 29, 2026, the Supreme Court issued its opinion in Watson v. RNC, a challenge to Mississippi’s state law that allows election officials to count ballots received no later than five business days after Election Day as long as they are postmarked by Election Day. In a close 5-4 decision, the court upheld the Mississippi law. It held that state laws that provide similar grace periods for mail ballots with Election Day postmarks do not violate existing federal law.

What Was the Case About?

The Mississippi Republican Party, the Republican National Committee, and two Mississippi voters initially challenged the Mississippi law in federal district court. The district court upheld the grace period law. The Fifth Circuit Court of Appeals reversed that ruling and held that federal law establishing a “single Election Day” requires all ballots to be received by Election Day, even if mailed on time. The state of Mississippi appealed the Fifth Circuit decision to the Supreme Court. The June 29 Supreme Court ruling reversed the Fifth Circuit’s ruling and reinstated Mississippi’s grace period law.

What Did the Supreme Court Say?

Justice Barrett wrote the opinion for the majority, which consisted of her, Chief Justice Roberts, and Justices Sotomayor, Kagan, and Jackson. Justice Barrett’s opinion noted that the defining element of when an “election” occurs is when voters make their choices, not when election officials receive ballots. Since postmark grace period laws require voters to make their choices by Election Day, nothing in the federal statute defining Election Day conflicts with those state laws. 

The opinion also discusses other federal statutes, such as the Uniformed and Overseas Citizens Absentee Voting Act. Justice Barrett noted that federal law may determine the deadline by which ballots must be cast, but state law controls the deadline by which they must be received. The opinion goes on to discuss several other examples of federal statutes that leave the decision of when ballots must be received to the states.

The majority opinion rejects the arguments based on historical practices that the Republican Party challengers and the Trump administration, represented by the Solicitor General, relied upon in their briefs and oral argument. Justice Barrett notes that, at its core, this was a case about statutory interpretation rather than upholding historical practice. She also noted that reliance on historical arguments may call into question other popular innovations in elections, such as in-person early voting. 

Since the federal statutes at issue in the case do not address ballot receipt, the Constitution leaves those decisions to the states. The opinion concludes that all the arguments presented by the challengers regarding “election integrity” and voter confidence are matters for state legislatures, not federal courts.

What Does the Ruling Mean Going Forward?

The Supreme Court’s decision means that the current laws in 14 states plus D.C. that provide a grace period for ballots postmarked by Election Day can remain in effect for all elections unless the legislatures in those states decide otherwise. Additionally, the laws in 30 states that provide a grace period for ballots returned by military and overseas voters can also remain in effect. Leaving these laws intact will prevent late changes to election administration that could cause confusion and chaos for voters and election administrators ahead of this November’s midterm elections. 

The Watson ruling also raises additional doubts about President Trump’s March 25, 2025, executive order that sought to impose new federal requirements on election administration. Among its provisions, that order, citing the same federal statutes at issue in Watson, attempted to impose a nationwide ban on mail-ballot grace periods for federal elections.

The Supreme Court’s decision that federal statutes do not conflict with state grace-period laws removes the justification for those proposals in the executive order. While that executive order is already subject to several injunctions issued by various federal courts, the Watson decision raises new arguments against its enforceability.