I posted about this here just a few days ago, and I thought it worthwhile to post this link Nick Carbone posted to tech-rhet as part of the on-going set of lessons from the 2004 electoral maps. This analysis (by some folks in computer science at U of M) goes even further in reconfiguring the red, blue, and purple maps by adding a proportional element.
For example, while Rhode Island is considerably smaller geographically than Wyoming, it has twice as many people. So on this map, Rhode Island is twice as big as Wyoming, though neither of them are really that large in this map.
This gets a little weird-looking when they start rearranging the purple maps, but I guess that’s their point: we really aren’t red and blue states as simply as been portrayed.