This link points to a network map by Valdis Krebs.
Divided We Stand... StillLast year I created a network map of political books based on purchase patterns from major web book retailers. The network revealed a divided populace... at least amongst book readers. I was curious to see what, if anything, had changed in the patterns in 2004.
I used the political books on the New York Times Bestseller List as a starting point for 'snowball sampling'. In the network map above, two books are linked if they were bought together. The network is organized and displayed by an algorithm that looks at the pattern of connections and finds the emergent structure. Nodes with only one or two links, and unrelated clusters that had no bridging role, were removed for clarity.
It appears that the many of the books have changed from last year but the pattern is the same. Two distinct clusters, with dense internal ties have emerged. These political books are preaching to the converted! This year we find more bridges between the clusters. Yet, this network of 67 books is dependent on just 2 nodes to remain connected -- Sleeping with the Devil and Bush at War.
So, if you are working a 2004 political campaign what do you do with this information? Obviously you will not be successful in removing a reader from deep in one cluster and transplanting them into the other cluster. All you can do is focus on the edge nodes and the bridges. See someone reading Sleeping with the Devil? That is someone you can talk to about your candidate. If they are reading Bushwacked or Dereliction of Duty -- the most central books in each cluster -- then either give them a high-five or a sneer, you won't change their views.
There are disappointingly few bridges between the red and blue. If readers were truly interested in understanding and learning they would confront a more diverse set of views than this picture suggests. Of course if they were really interested in learning they probably wouldn't have bought any of these books.