From SCOTUSblog and the question presented:

Federal law sets the first Tuesday after the first Monday in November as the federal Election Day. 2 U.S.C. §§ 1 and 7; and 3 U.S.C. § 1. Several states, including Illinois, have enacted state laws that allow ballots to be received and counted after Election Day. Petitioners contend these state laws are preempted under the Elections and Electors Clauses. Petitioners sued to enjoin Illinois’ law allowing ballots to be received up to fourteen days after Election Day.

The sole question presented here is whether Petitioners, as federal candidates, have pleaded sufficient factual allegations to show Article III standing to challenge state time, place, and manner regulations concerning their federal elections.

The Seventh Circuit found no standing. It’s in contrast to the Fifth Circuit, which had found standing on a related issue. Of course, the underlying issue of receiving absentee ballots is a merits question that the Court will assiduously avoid, but one that could tee up the dispute later.