Voting rights advocates in Alaska are worried that a case set to be heard by the U.S. Supreme Court could end a long-standing practice of the state accepting ballots after Election Day. The justices are set to hear arguments Monday in a case challenging Mississippi’s grace period for ballots postmarked by Election Day but received afterward. Perhaps nowhere will a ruling against Mississippi have as profound an effect as in Alaska. The state's vastness, its number of remote villages and inherent challenges in getting ballots to vote-counting centers are among the reasons it allows a 10-day grace period for receiving ballots.