On Monday the Supreme Court will hear a challenge to Mississippi’s mail‑in ballot rule that permits ballots postmarked by Election Day to be counted if they arrive within five business days after the vote. The Republican National Committee and the state GOP filed the suit, arguing the provision conflicts with federal election statutes.

The dispute centers on whether federal law setting a single Election Day date bars states from adopting their own late‑arrival policies. A 2024 district judge upheld the rule, but the Fifth Circuit reversed