The Supreme Court brought an end to the independent state legislature theory which said only legislatures have the authority to regulate federal elections, and state courts cannot interfere. In Moore v. Harper, the justices ruled 6-3 that the Constitution’s elections clause does not vest exclusive and independent authority in state legislatures to set the rules regarding federal elections. 

The court’s three liberal justices and three of the conservative justices formed the majority, while Justices Gorsuch, Thomas and Alito dissented. 

Chief Justice John Roberts wrote in the majority opinion, “…when legislatures make laws, they are bound by the provisions of the very documents that give them life.”

Roberts went on to write, “The idea that courts may review legislative action was so ‘long and well established’ by the time we decided Marbury in 1803 that Chief Justice Marshall referred to judicial review as ‘one of the fundamental principles of our society.’” 

But the majority also cautioned that state courts cannot overstep their authority and take it upon themselves to regulate federal elections. The justices declined to create a specific test to judge state court interpretations because they said the matter is too complex and context specific. It will be done on a case-by-case basis. 

This case originated in North Carolina after the state Legislature challenged a court ruling that the state’s new congressional maps were gerrymandered and should be redrawn by an expert panel. But since that time, the North Carolina Supreme Court reversed that decision, so the U.S. Supreme Court’s new ruling will not have an impact on that case. 

Justices Thomas, Alito and Gorsuch dissented for that exact reason, stating the case was moot. 

“[The court] ‘affirms’ an interlocutory state-court judgment that has since been overruled and supplanted by a final judgment resolving all claims in petitioners’ favor. The issue on which it opines — a federal defense to claims already dismissed on other grounds — can no longer affect the judgment in this litigation in any way. As such, the question is indisputably moot, and today’s majority opinion is plainly advisory,” Justice Thomas wrote. 

But the majority stated precedent requires a decision to be made when the overall federal issue is still at question.