People gather outside the U.S. Supreme Court building in Washington, D.C., U.S., March 14, 2026. Will Dunham | Reuters Conservative U.S. Supreme Court justices signaled skepticism on Monday toward a Mississippi law challenged by Republicans that allows a five-day grace period for mail-in ballots received after Election Day to be counted in a case that could lead to stricter voting rules around the country. Republican President Donald Trump’s administration argued in favor of the challenge to Mississippi’s law, which permits mail-in ballots sent by certain voters to be counted if they were postmarked on or before Election Day but received up to five business days after a federal election. Absentee voting by mail is limited to a few categories of voters under the law including elderly people, the disabled and those living away from home. The Supreme Court heard arguments in Mississippi’s appeal of a lower court’s ruling that deemed its mail-in ballot law illegal. The dispute centered on whether federal laws setting Election Day for federal elections preempt state laws in various states that …