Gerrymandered House Districts

The map above is from Christopher Ingraham in the Washington Post. It shows the most gerrymandered House Districts in the United States. The most obvious gerrymandered districts are those with the darkest color. The states with the most districts that are obviously gerrymandered are North Carolina, Texas, Pennsylvania, Ohio, and Kentucky -- but they are far from the only states with gerrymandered districts. Ingraham used a "compactness" test to determined the districts most likely to be gerrymandered. Here is what he said:

Contrary to one popular misconception about the practice, the point of gerrymandering isn't to draw yourself a collection of overwhelmingly safe seats. Rather, it's to give your opponents a small number of safe seats, while drawing yourself a larger number of seats that are not quite as safe, but that you can expect to win comfortably. . .

The compactness of a district --  a measure of how irregular its shape is, as determined by the ratio of the area of the district to the area of a circle with the same perimeter --  can serve as a useful proxy for how gerrymandered the district is. Districts that follow a generally regular shape tend to be compact, while those that have a lot of squiggles and offshoots and tentacle-looking protuberances tend to score poorly on this measure.

Using district boundary files from the Census, I calculated compactness scores for each of the districts of the 113th Congress and mapped them so you can see where the least compact -- and likely most-gerrymandered --districts are.