The Supreme Court heard arguments Wednesday about an Illinois law that allows ballots to be counted that arrive up to 14 days after Election Day.
The plaintiffs, Rep. Mike Bost, R-Ill., and two presidential electors from the state, contend that federal law established Election Day and Illinois allows votes to come in two weeks longer than federal law allows, which would make such ballots effectively unlawful. Thus, unlawful ballots could cost Bost the election—or reduce his margin for victory.
The plaintiffs also argued the Bost campaign is further injured because it has to pay staff for an additional two weeks after the election.
Plaintiffs are represented by the watchdog group Judicial Watch.
Federal law 2 U.S. Code Section 7 states Election Day for federal offices is the Tuesday after the first Monday of November in even-numbered years.
Illinois says mail-in ballots must be postmarked by Election Day but can arrive up to two weeks later.