The Great Gerrymander of 2012
February 2, 2013
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 a progress 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.
In North Carolina, where the two-party House vote was 51 percent Democratic, 49 percent Republican, the average simulated delegation was seven Democrats and six Republicans. The actual outcome? Four Democrats, nine Republicans — a split that occurred in less than 1 percent of simulations. If districts were drawn fairly, this lopsided discrepancy would hardly ever occur.
http://www.nytimes.com/2013/02/03/opinion/sunday/the-great-gerrymander-of-2012.html?pagewanted=all