They vote by night

Among all the fascinating maps that’ve been made of the US voting patterns for the 2008 presidential election, I couldn’t find the one I really wanted to see: a map showing both voter percentages and population density on an undistorted projection. With fancy databases it wouldn’t be hard to do, but I did come up with a way to Photoshop an approximation, combining the red-blue-purple county-percentage map from the University of Michigan with the famous satellite image of nighttime illumination. It’s not a total match for population—gas flares get counted as voters, for instance—but it comes closer than anything I’d found Composite image by Nate Barksdale from NOAA and UM sources linked below, 9 November 2008