Parsing the Red and Blue Map
Physics professor Mark Newman has a thing for maps. He co-authored The Atlas of the Real World, a volume that features cartograms, maps in which a mathematical variable is substituted for land area. This causes traditional land-based maps to skew and distort in bizarre ways, hopefully communicating important information to the viewer -- information that goes beyond what you can see when just looking at land area.
Newman's cartograms of the 2008 election map have been making the rounds of the web, and I highly recommend a look at them. It's a quick read, and is a great introduction to how the process of cartogramography can change how we think about maps. Below are two sample illustrations from Newman's page.
Traditional red state/blue state map, 2008 election edition:
Cartogram redrawing the map with states proportional to their populations:
...But that's hardly the end of the story -- no state is entirely red or entirely blue. Check out Newman's cartograms for further analysis of how to look in detail at electoral mapping, to get a better view of the US election. (Hint: it's not about red or blue, it's about purple.)