Not only are crossover representatives disappearing, but the number of districts that are at all competitive has also drastically declined. In over 80% of congressional districts there is essentially no chance of victory for a candidate from the party in the minority in 2014. This lack of competition not only prevents the election of crossover legislators, but ensures that the candidates who are elected need only be concerned with the views of their partisan primary voters, who become the de facto electorate.
Though declining competition in U.S. House races is often blamed on redistricting and partisan gerrymandering, it has more to do with demographic forces and the self-sorting of Americans into pockets of like-minded voters than with partisan attempts to manipulate the electoral landscape. More than ever before, Democratic voters are concentrated in urban areas, while conservatives are in the majority outside of cities. This divide means that no matter how district lines are drawn, winner-take-all House elections will remain uncompetitive and generate an artificially polarized chamber. That is why half-measures like independent redistricting are insufficient for addressing the underlying forces that have broken Congress and led to the shutdown.