If you’ve been following the 2014 midterm elections, you know there’s very little chance that the U.S. House of Representatives will go blue this year. One reason is gerrymandering, where congressional districts are redrawn to either pack opposing voters into one district or spread them out among districts in a less popular divide-and-conquer strategy. Both parties do it. But in the last midterm election, in 2010, the strategy proved a winner for Republicans, who dominate the state legislatures that control district boundaries in most states. In that contest, in the seven states where the district maps were drawn by Republicans, the actual votes cast for each party were fairly close: 16.4 million for Democrats, 16.7 million for Republicans. But those numbers resulted in a much starker 73 Republicans and 34 Democrats ultimately elected.
As technology has made it easier to draw boundaries with microscopic precision, and as the parties have sorted themselves geographically, gerrymandering has dramatically changed the American political landscape—so much so that its creators don’t go to any real efforts to conceal the conspicuously strange shapes they create.
There’s a reason no one is talking about the races in the House this November: These 10 maps, of the most gerrymandered districts in America according to a 2012 study by geospatial software firm Azavea, go a long way in explaining why.