Trader consensus on Polymarket prices a 72% implied probability that SCOTUS will bar counting mail-in ballots received after Election Day, driven primarily by oral arguments in the Watson v. RNC case on March 23, 2026. Conservative justices expressed strong skepticism toward Mississippi's grace period law, questioning whether federal statutes establishing a single uniform Election Day—such as 52 U.S.C. § 20301—preempt state extensions for late-arriving absentee ballots. No decision has issued yet, but the Court's signals, echoing precedents like Foster v. Love, have shifted odds upward amid 2026 midterm preparations. Election officials warn of processing disruptions, while a recent Virginia redistricting appeal invokes similar federal Election Day arguments, heightening stakes ahead of an expected ruling.