RALEIGH, N.C. (AP) - Voters who successfully sued over North Carolina's 2011 legislative districts say federal judges did the right thing directing an outside expert to recommend more changes to boundaries amended last summer but that could still be unconstitutional.

Attorneys for these voters filed Wednesday a document designed to counter arguments of Republican lawmakers who say it was wrong for the judges to hire a special master for remapping recommendations.

The lawyers say the recommendations remove continued racial bias in four districts and state constitutional violations elsewhere. GOP lawmakers say these problems don't exist and want judges to sign off on House and Senate districts approved last August.

The three-judge panel won't rule until at least January. Republican lawmakers plan to appeal to the U.S. Supreme Court if the expert's changes are approved.