Another redistricting lawsuit has been filed in North Carolina, this one challenging General Assembly boundaries that Democrats and election reform advocates say are illegally tainted by excessive favoritism toward Republicans.

Common Cause NC, the state Democratic Party and voters sued GOP mapmakers Tuesday in Wake County court.

Partisan gerrymandering claims against state legislative lines are similar to those Common Cause and the party filed two years ago in federal court over state congressional districts. Federal judges have twice ruled the congressional map violated protections for Democratic voters. The U.S. Supreme Court is considering whether to hear an appeal in that case.

Tuesday’s lawsuit is different because it focuses on the North Carolina Constitution.

At least eight lawsuits have challenged North Carolina maps since the current redistricting round began in 2011.