The U.S. Supreme Court’s conservative justices signaled their willingness on Wednesday to undercut another key section of the Voting Rights Act, the landmark 1965 federal law enacted by Congress to prevent racial discrimination in voting.

Questions they posed during arguments in a major case involving Louisiana electoral districts reflected an interest in curbing the Voting Rights Act’s Section 2, which bars voting maps that would result in diluting the clout of minorities, even without direct proof of racist intent.