Mail-in voting challenge at Supreme Court could affect WA elections

The U.S. Supreme Court on Monday took up a Republican-backed challenge to counting mail-in ballots received after Election Day.

Depending how the justices rule, the case could be consequential for Washington and other states that vote by mail.

It stems from a lawsuit against a Mississippi state law allowing mail-in ballots received within five business days after Election Day to still be counted. Roughly 30 states have similar laws, with varying grace periods.

The decision could also have ramifications for next year’s high-stakes midterms, which will decide whether Republicans maintain control of both the U.S. House and Senate. The court will likely hear arguments and rule by mid-2026.

Washington is one of a handful of states that conduct elections by mail and ballot drop boxes. The st