The U.S. Supreme Court heard arguments earlier this month in a case that could decide whether political candidates have the right to challenge Illinois’ vote-by-mail law in court.

U.S. Rep. Mike Bost (R-Murphysboro) and a pair of Illinois primary delegates for President Donald Trump sued the Illinois State Board of Elections in 2022, arguing the state’s law allowing late-arriving mail-in ballots to be counted up to 14 days after the polls close violates the federal law establishing an “Election Day.”

Both a lower federal trial court and federal appeals court have ruled Bost lacked standing to sue.

Republicans at both the state and national levels embraced mail-in voting in the 2024 election cycle after pushing back against it in recent years. The Illinois Republican Party joined the Republican National Committee’s “bank your vote” initiative, which encouraged reliable Republican voters to vote early or by mail so campaigns could focus resources on turning out people who were undecided.

The Supreme Court’s ruling will focus on whether Bost, in his role as a political candidate, has legal grounds to sue over the state’s election law. It will not decide whether Illinois’ mail-in voting law is constitutional. However, a favorable ruling for Bost by the nation’s high court would allow his challenge to proceed at a lower level, opening the door for courts to rule on counting mail-in votes after an election.

Illinois Solicitor General Jane Notz, defending the case for the State Board of Elections, faced challenging questions from the justices. At one point, Justice Brett Kavanaugh warned Notz she was giving an argument contrary to a written argument filed with the court.

Bost argues he has a right to sue because he suffers financial injury by paying campaign staff for two weeks beyond the election to monitor ballot counting. He also argued his vote total might be diluted if more votes are counted after election night.

As a candidate for office, Bost is directly impacted by election laws, Bost’s attorney Paul Clement argued.

Winning elections has not been a problem for Bost. He has represented the 12th Congressional District in Southern Illinois since 2015 and was re-elected in 2024 with nearly 75 percent of the vote.

(Information courtesy of Capitol News Illinois)