The Supreme Court is about to confront a new elections case, a Republican-led challenge asking the justices for a novel ruling that could significantly increase the power of state lawmakers over elections for Congress and the presidency.

The court is set to hear arguments Wednesday in a case from North Carolina, where Republican efforts to draw congressional districts heavily in their favor were blocked by a Democratic majority on the state Supreme Court because the GOP map violated the state constitution.

A court-drawn map produced seven seats for each party in last month’s midterm elections in highly competitive North Carolina.

The question for the justices is whether the U.S. Constitution’s provision giving state legislatures the power to make the rules about the “times, places and manner” of congressional elections cuts state courts out of the process.

“This is the single most important case on American democracy — and for American democracy — in the nation’s history,” said former federal judge Michael Luttig, a prominent conservative who has joined the legal team defending the North Carolina court decision.

The Republican leaders of North Carolina’s legislature told the Supreme Court that the Constitution’s “carefully drawn lines place the regulation of federal elections in the hands of state legislatures, Congress and no one else.”

Three conservative justices already have voiced some support for the idea that the state court had improperly taken powers given by the Constitution when it comes to federal elections. A fourth has written approvingly about limiting the power of state courts in this area.