BETTER THAN A CARTOGRAM!
A mixed density visualization...
...of both the volume and proportion of vote.
By John Nelson
It's been suggested that this map could go a step further, into dasymetric territory:
Dasymmentric map - "Considered a hybrid or compromise between isopleth and choropleth maps a dasymetric map utilizes standardized data, but places areal symbols by taking into consideration actual changing densities within the boundaries of the map. If appropriately approached it is far superior to choropleth maps in relaying statistical data within areas of interest. Dasymetric mapping corrects for error, termed 'ecological fallacy,' that may occur with choropleth mapping." -- the great Wikipedia, and some broken links attached to it.
And here are some election pointillist maps of Dallas-Fort Worth, from Kirk Goldsberry:
Description from New Scientist:
"The top half shows how people voted. Each red dot, unsurprisingly, is a Republican voter, while blue indicates Democrats. On the bottom half, each dot represents four people: blue is Asian, pink is black, green is Hispanic and orange is white."