The court repudiated the independent state legislature theory, which could have transformed elections for Congress and president.
WASHINGTON -- The Supreme Court on Tuesday ruled in a case that threatened to upend state election laws nationwide.
It involved who gets to decide when, where and how Americans vote - and whether state courts can provide a check on the process.
A 6-3 decision by Chief Justice John Roberts rejects a broad interpretation of the so-called "independent state legislature" theory.
The court ruled against Republican lawmakers in a dispute over a North Carolina congressional map.
Roberts was joined by Justices Sonia Sotomayor, Elena Kagan, Ketanji Brown Jackson, Brett Kavanaugh and Amy Coney Barrett.
In Moore v. Harper, the justices were asked to reinstate the state legislature's gerrymandered voting map after the North Carolina Supreme Court struck it down for violating the state constitution.
At the heart of the case was a controversial legal concept dubbed the "independent state legislature" theory, which contends the Elections Clause of the U.S. Constitution provides state legislators alone the power to govern federal elections unencumbered by traditional oversight from state constitutions, courts and governors.
Election and democracy experts warned the theory, if adopted in its most extreme application, could have a dramatic impact on how elections are run and voting rules are written in the U.S.
The Supreme Court on Tuesday rejected the theory, with Chief Justice Roberts writing the Elections Clause "does not insulate state legislatures from the ordinary exercise of state judicial review."Justices Clarence Thomas, Neil Gorsuch and Samuel Alito dissented.
"In interpreting state law in this area, state courts may not so exceed the bounds of ordinary judicial review as to unconstitutionally intrude upon the role specifically reserved to state legislatures by Article I, Section 4, of the Federal Constitution," Roberts wrote.
In their dissent, Justices Thomas, Gorsuch and Alito argued the case should have dismissed given state-level developments. The North Carolina Supreme Court, under a new Republican majority, in April reversed its previous ruling that said the gerrymandered maps were illegal.
"This is a straightforward case of mootness," Thomas wrote. "The federal defense no longer makes any difference to this case- whether we agree with the defense, disagree with it, or say nothing at all, the final judgment in this litigation will be exactly the same."
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