NextFin

Supreme Court Considers Reviving Illinois Congressman’s Lawsuit Challenging State Mail-In Ballot Law

NextFin news, On Wednesday, October 8, 2025, the U.S. Supreme Court convened in Washington, D.C., to hear oral arguments in a case that could determine whether U.S. Rep. Mike Bost, a Republican from Murphysboro, Illinois, has the legal standing to challenge Illinois’ mail-in voting law.

Bost and two Illinois primary delegates for former President Donald Trump filed the lawsuit in 2022 against the Illinois State Board of Elections. They argue that the state’s law, enacted in 2015, which permits mail-in ballots postmarked by Election Day to be counted if received up to 14 days after the election, violates federal law that establishes a single Election Day.

Lower federal courts have previously dismissed Bost’s lawsuit, ruling that he lacked standing to sue. Bost’s legal team contends that as a candidate, he suffers financial harm because his campaign must allocate resources to monitor ballot counting for two weeks beyond Election Day. They also argue that late-counted ballots could dilute his vote total.

During the nearly two-hour oral arguments, Supreme Court justices questioned attorneys from both sides about the criteria for who may have the right to sue over election regulations. The justices focused on whether Bost, as a political candidate, has a concrete and particularized injury sufficient to grant him standing.

Bost’s attorney, Paul Clement, argued that candidates are directly impacted by election laws and should be allowed to challenge them regardless of their margin of victory or likelihood of winning. He emphasized that even candidates with minimal chances of winning should have the right to seek judicial review of election rules that affect their campaigns.

Conversely, Illinois Solicitor General Jane Notz, representing the State Board of Elections, argued that the law regulates voters, not candidates, and that Bost’s acknowledged strong electoral record undermines his claim of injury. She warned that granting standing to any candidate dissatisfied with election rules could lead to excessive litigation and distract election officials from administering elections.

Justices expressed varying views on the issue. Justice Sonia Sotomayor questioned the appropriateness of allowing candidates without a close race to sue, while Justice Neil Gorsuch suggested that standing should not depend on a candidate’s chances of winning. Justice Ketanji Brown Jackson raised concerns about opening the door to numerous lawsuits from losing candidates seeking to alter election outcomes.

The Supreme Court’s decision will not address the constitutionality of Illinois’ mail-in voting law itself but will determine whether Bost’s challenge can proceed in lower courts. A ruling in Bost’s favor would revive the lawsuit and potentially lead to further judicial scrutiny of the state’s mail-in ballot counting procedures.

The court is expected to issue its ruling on the standing question by June 2026.

Explore more exclusive insights at nextfin.ai.

Open NextFin App