Having the first modern democracy comes with bugs. Normally we would expect more seats in Congress to go to the political party that receives more votes, but the last election confounded expectations. Democrats received 1.4 million more votes for the House of Representatives, yet Republicans won control of the House by a 234 to 201 margin. This is only the second such reversal since World War II. Using statistical tools that are common in fields like my own, neuroscience, I have found strong evidence that this historic aberration arises from partisan disenfranchisement. Although gerrymandering is usually thought of as a bipartisan offense, the rather asymmetrical results may surprise you. Through artful drawing of district boundaries, it is possible to put large groups of voters on the losing side of every election. The Republican State Leadership Committee, a Washington-based political group dedicated to electing state officeholders, recently issued aprogress report on Redmap, its multiyear plan to influence redistricting. The $30 million strategy consists of two steps for tilting the playing field: take over state legislatures before the decennial Census, then redraw state and Congressional districts to lock in partisan advantages. The plan was highly successful.
I have developed approaches to detect such shenanigans by looking only at election returns. To see how the sleuthing works, start with the naïve standard that the party that wins more than half the votes should get at least half the seats. In November, five states failed to clear even this low bar: Arizona, Michigan, North Carolina, Pennsylvania and Wisconsin.
Now let’s do something more subtle. We can calculate each state’s appropriate seat breakdown — in other words, how a Congressional delegation would be constituted if its districts were not contorted to protect a political party or an incumbent. We do this by randomly picking combinations of districts from around the United States that add up to the same statewide vote total. Like a fantasy baseball team, a delegation put together this way is not constrained by the limits of geography. On a computer, it is possible to create millions of such unbiased delegations in short order. In this way, we can ask what would happen if a state had districts that were typical of the rest of the nation.
Full Article: The Great Gerrymander of 2012 – NYTimes.com.