A picture of party identification

Political scientist David Sparks has posted several interesting isarithmic maps of public opinion data—sort of pictures of national public opinion.  The map below shows party identification across the country—blue Democrat to red Republican.  Darker and lighter areas indicate levels of response density reflecting the degree of polling and number of residents.  You can view other similar maps of public opinion by Sparks here:  http://dsparks.wordpress.com/2011/10/24/isarithmic-maps-of-public-opinion-data/