I was looking at the amazing 2012 election maps created by Robert J. Vanderbei (Princeton) and Mark Newman (Department of Physics and Center for the Study of Complex Systems, University of Michigan), and although there is a very interesting blended voting map (Most of the country is some shade of purple, a varied blend of Democrat blue and Republican red) what I really wanted was this blended map with a population density overlay.

Best map of the election that I've seen so far.