In some ways, I still like Massinc's Commonwealth Project ten regions more, in terms of dividing the country into regions based on voting proclivities.
although clearly they haven't updated it since 2000, as promised
http://www.massinc.org/index.php?id=110&pub_id=1618But for the purposes of giving a test and boxing you according to your answers to several questions and determining matches, I like this 13-region thing better, since it separates the pacific west from Back East. What it doesn't do, is separate New England, Pennsylvania, or Florida into the radically different political regions like the Commonwealth Project does. For example, Miami and Destin are put into the same "peripheral south" even though the combination of caribbean immigrants and new york jews in the former have different priorities than the condo owners and sunworshipping residents of Destin and Panama City, most of whom hail from Georgia and Alabama.