Supreme Court upholds Mississippi law counting late-arriving mail ballots

The Supreme Court on June 29, 2026, upheld Mississippi’s law allowing mailed ballots postmarked by Election Day to be counted if they arrive within five business days. The 5-4 ruling preserves a grace period that also exists in similar forms in other states.

Justice Amy Coney Barrett wrote for the majority. Chief Justice John Roberts joined Barrett and the court’s three liberal justices, while Justices Samuel Alito, Clarence Thomas, Neil Gorsuch and Brett Kavanaugh dissented in whole or in part, according to coverage of the ruling.

The case, identified in coverage as Watson v. Republican National Committee, turned on a basic question with major election consequences: whether federal election law requires mailed ballots to be received by Election Day, or whether a timely postmark is enough when state law allows later arrival.

The Republican National Committee and aligned challengers argued that ballots must be in hand by Election Day. The court rejected that reading and left Mississippi’s ballot-counting rule in place.

What Mississippi’s law does

Mississippi’s rule allows a mailed ballot to count if it is postmarked by Election Day and arrives within five business days. The Supreme Court’s decision means that rule remains valid for the state’s elections.

The dispute reached the justices after the Fifth Circuit had ruled against Mississippi’s ballot-counting rule. The high court’s decision reverses that outcome and restores the state’s approach.

Coverage of the ruling says the decision also preserves similar grace periods in 14 states, along with Washington, D.C., and three U.S. territories. That makes the opinion significant well beyond Mississippi.

Why the ruling matters

The practical impact is largest in close elections, where mailed ballots can be sent on time but arrive after Election Day. Under Mississippi’s law, those ballots still count if they meet the postmark and grace-period requirements.

Coverage cited more than 750,000 mailed ballots in the 2024 general election that were mailed on time and arrived after Election Day in states with grace periods. That figure shows how many votes can be affected by the deadline rule.

The ruling does not create a single national mail-ballot standard. It does, however, preserve state systems that give voters a limited window for ballots that were timely postmarked but delayed in transit.

The broader election-law fight

The case lands in the middle of a broader national fight over mail voting, ballot deadlines and the balance between federal election law and state control over election administration.

States differ on how long ballots may take to arrive after Election Day, and the ruling leaves those state choices intact where local law permits them. That matters because grace-period systems are used in both red and blue states.

The decision also clarifies the legal backdrop for election officials who process absentee and mail ballots under state deadlines that extend beyond Election Day. For those states, the counting window remains available unless and until their laws change.

What comes next

The immediate question is how Mississippi election officials and other states with similar rules respond before the next election cycle. The ruling should remove uncertainty about whether timely postmarked ballots can still be counted under those laws.

Another open issue is whether the Republican National Committee or other challengers will pursue narrower follow-up litigation. Coverage also raises the possibility of state-level changes to ballot-processing rules, though no such changes were identified in the reporting packet.

For now, the court’s decision is the controlling word on Mississippi’s grace-period law and similar late-arrival ballot rules. It preserves a counting practice that could matter in thousands of ballots in close races.