Editor's note: This excerpt is from a Law360 Expert Analysis.

"The rules that govern elections should be clear, well established and settled well in advance of the election. Few would disagree about that.

Voters, political parties and candidates all benefit from these rules being clear and settled well before the voting process begins. When the rules are clear in advance, voters are more likely to know them, and all actors in the process can plan and coordinate their actions around the rules. Clear rules specified in advance also enhance general confidence in the integrity of the process.

These principles are all the more powerful now that our elections take place in a time of pervasive distrust about the election process. These considerations pose challenges, as well, for the appropriate timing of any federal court adjudication concerning election rules.

On Oct. 8, the U.S. Supreme Court will hear oral arguments in a major election law case, Bost v. Illinois State Board of Elections, that implicates precisely these issues.

Although the substantive issue underlying the Bost case is whether Illinois' absentee ballot receipt deadline violates federal law, the court granted review only on a more general and important question of standing: whether candidates for office have standing to bring prospective challenges to election laws and, if so, under what circumstances.

The case began as a challenge to an Illinois law that permits absentee ballots cast in federal races to be counted if they are received up to two weeks after Election Day, so long as they are postmarked by Election Day. The petitioners — Rep. Mike Bost, a sitting Republican member of Congress, along with two Republican presidential electors — argue that this policy conflicts with the federal statute establishing a single, uniform Election Day for federal elections.

They also allege that the policy violates a provision of the Electoral Count Reform and Presidential Transition Improvement Act, passed in 2022, providing that presidential electors "be appointed ... on election day."

Illinois enacted its absentee ballot receipt rule in 2005, amid a broader national shift toward modernizing election administration. Today, more than a dozen states provide some form of post-Election Day grace period for receipt of absentee ballots, with Illinois' two-week window among the most expansive. These statutes permit absentee voters to cast a ballot as late as Election Day, and reflect concerns that potential postal delays should not disenfranchise voters who have cast — that is, properly postmarked — their ballots by Election Day.

In recent years, however, as absentee voting has become a source of controversy, some states — including, most recently, Utah, North Dakota and Kansas — have eliminated their post-Election Day receipt deadlines and required all ballots to be returned by Election Day.

Bost's suit from Illinois is part of a more general effort to persuade the Supreme Court that, despite years of practice to the contrary, federal law requires all ballots in federal elections to be returned by Election Day. Republican candidates and elected officials, as well as Republican Party organizations, have brought similar lawsuits challenging post-Election Day receipt deadlines in several states. Some of these have been dismissed on standing grounds; others have reached the merits.

Last October, in Republican National Committee v. Wetzel, the U.S. Court of Appeals for the Fifth Circuit reversed the U.S. District Court for the Southern District of Mississippi and became the first federal court to hold that federal law prohibits the counting of ballots received after Election Day.

In that case, the Fifth Circuit held that Mississippi's post-Election Day receipt deadline of five business days is preempted by federal statutes establishing a uniform Election Day. This is also Bost's argument. Mississippi's petition for certiorari is now pending before the Supreme Court, and given the conflict in the lower courts on this important issue, it is likely the court will agree to hear that case.

But in the Bost case, the merits of Illinois' policy are not before the court. In a 2-1 decision, the U.S. Court of Appeals for the Seventh Circuit held last August that the petitioners lacked standing, whether in their capacity as registered voters or as candidates for office. Whereas an injury-in-fact must be concrete, particularized and imminent, the majority characterized Bost's alleged harms as "speculative at best" at this stage.

The question now before the court is who, if anyone, can allege a judicially cognizable injury in prospective cases raising federal law challenges to election rules…"

Read the full piece here.