I thought this project Stanford did was well-done. It's a map of 2008 presidential election precinct results but instead of using a choropleth map, they use dots of varying sizes and colors to represent party preference. When you zoom in or out, the image resolves so that the dots are an appropriate size. You can also view as separate layers by census tracts the predominant race, median household income, and number of potential voters. It might be a good resource if someone wants to do a choropleth map instead of a dot map, but then again it doesn't provide shapefiles or names of precincts, etc., etc. But I wouldn't be surprised if political campaigns referenced this project in the future.
http://atlas.esri.com/Atlas/VoterAtlas.html