The U.S. Supreme Court will hear arguments Monday about mail-in voting in Mississippi and whether the state's ballot deadline is valid.

If Mississippi loses this fight at the Supreme Court, it could mean major changes to how mail-in ballots are counted everywhere.

If Mississippi loses this fight at the Supreme Court, it could mean major changes to how mail-in ballots are counted everywhere.

The U.S. Supreme Court is to hear Monday a legal case that could have ramifications on mail-in balloting deadlines in the upcoming mid-term elections.

The U.S. Supreme Court will hear arguments Monday about mail-in voting in Mississippi and whether the state's ballot deadline is valid.