North Carolina’s state legislative maps are so severely gerrymandered to benefit Republicans that they violate the state’s Constitution, a panel of three judges ruled Tuesday.

The ruling came in a closely watched case in North Carolina state court. State lawmakers have until Sept. 18 to draw new districts, the court said, and they won’t be allowed to take into account any data about election results.

Lawmakers will also be banned from using the existing maps as a “starting point” as they draw new maps and will be required to draw maps entirely in public view, the court ruled. Any computer screen the lawmakers use, the court said, has to be fully visible to lawmakers and public observers.

“Extreme partisan gerrymandering does not fairly and truthfully ascertain the will of the people,” the judges wrote. “Voters are not freely choosing their representatives. Rather, representatives are choosing their voters. It is not the will of the people that is fairly ascertained through extreme partisan gerrymandering. Rather, it is the will of the map drawers that prevails.”

The case was decided by three superior court judges: Paul Ridgeway, Joseph Crosswhite and Alma Hinton. The judges noted in the opinion that they are each from different parts of the state and have differing “ideological and political outlooks.”

The case carries implications that go beyond North Carolina. In June, the U.S. Supreme Court ruled that federal courts can’t do anything to stop partisan gerrymandering. But activists believe litigation in state courts could offer a way to challenge partisan gerrymandering ― an idea that Tuesday’s ruling seems to bear out.

North Carolina Republicans controlled the redistricting process in the state in 2011 and drew congressional and state legislative district lines that significantly benefited GOP lawmakers. Republicans were consistently able to win more than 60% of the seats in both of the state’s legislative chambers despite winning only about half of the statewide vote. They enjoyed that veto-proof majority until 2018, when Democrats broke it.

The case, Common Cause v. Lewis, was brought on behalf of the advocacy group Common Cause, the North Carolina Democratic Party and a handful of Democratic voters throughout the state.