Gerrymandering is almost as old as the US republic itself. It’s the process of drawing electoral district lines in sometimes absurd ways to fortify one political party at the expense of another. Good-government groups say that gerrymandering lets politicians choose their constituents,

The Supreme Court ruled that Texas can redraw its electoral map to benefit Republicans. Last month a lower court struck down the state’s gerrymandering attempt, finding that it discriminated against black and Latino voters.