Amid all this ferment, Trump’s legal team is fine-tuning a constitutional argument that is pitched to appeal to a five-justice majority if the 2024 election reaches the Supreme Court. This, too, exploits the GOP advantage in statehouse control. Republicans are promoting an “independent state legislature” doctrine, which holds that statehouses have “plenary,” or exclusive, control of the rules for choosing presidential electors. Taken to its logical conclusion, it could provide a legal basis for any state legislature to throw out an election result it dislikes and appoint its preferred electors instead.

Elections are complicated, and election administrators have to make hundreds of choices about election machinery and procedures—the time, place, and manner of voting or counting or canvassing—that the legislature has not specifically authorized. A judge or county administrator may hold polls open for an extra hour to make up for a power outage that temporarily halts voting. Precinct workers may exercise their discretion to help voters “cure” technical errors on their ballots. A judge may rule that the state constitution limits or overrides a provision of state election law.

Four justices—Alito, Neil Gorsuch, Brett Kavanaugh, and Clarence Thomas—have already signaled support for a doctrine that disallows any such deviation from the election rules passed by a state legislature. It is an absolutist reading of legislative control over the “manner” of appointing electors under Article II of the U.S. Constitution. Justice Amy Coney Barrett, Trump’s last appointee, has never opined on the issue.

The question could arise, and Barrett’s vote could become decisive, if Trump again asks a Republican-controlled legislature to set aside a Democratic victory at the polls. Any such legislature would be able to point to multiple actions during the election that it had not specifically authorized. To repeat, that is the norm for how elections are carried out today. Discretionary procedures are baked into the cake. A Supreme Court friendly to the doctrine of independent state legislatures would have a range of remedies available to it; the justices might, for instance, simply disqualify the portion of the votes that were cast through “unauthorized” procedures. But one of those remedies would be the nuclear option: throwing out the vote altogether and allowing the state legislature to appoint electors of its choosing.