DOUGLAS GINSBURG, Federal Judge, U.S. Court of Appeals, D.C. Circuit:
The citizens in each congressional district elect their member of the House of Representatives. But many House elections are not really competitive. The district reliably votes either Democrat or Republican.

Some seats almost never change parties. Voters in many urban districts lean Democratic. Those in rural districts lean Republican. But some districts are designed to be uncompetitive through a process called gerrymandering – drawing congressional boundaries to favor one political party.
The Founders envisioned each congressional district as a cohesive area – like Maryland’s First Congressional District on its eastern coast … and unlike Maryland’s Third Congressional District, as it looked after the 2010 Census. It is so obviously gerrymandered that one politician said it resembled a “blood spatter from a crime scene.” One federal judge – not I – likened the shape of the district to that of “a broken-winged pterodactyl.”
Every ten years the congressional map is redrawn – usually by state legislatures. For the party in power, the goal of gerrymandering is to take a surplus of its voters from one district and move them to a more competitive district.
As a result, a district once evenly split between Democrats and Republicans gets an influx of one party’s voters – enough to win that district consistently. But a representative in a safe seat is often less willing to compromise with the other party. So compromise, which is necessary for legislating, is made more difficult by gerrymandering.
It may seem therefore, that with gerrymandering, representatives choose their voters. But in the end, it is voting citizens who choose their member of the House of Representatives.