Electoral Map in Motion

Duke University doctoral student David B. Sparks has created a way to depict decades of change in presidential voting (Republican vote in red, Democratic vote in blue):

Isarithmic History of the Two-Party Presidential Vote from d sparks on Vimeo.

Using county-level data, I spatially and temporally interpolated presidential vote returns for the two major party candidates in each election from 1920-2008. The result illuminates the sometimes gradual, sometimes rapid change in the geographic basis of presidential partisanship.

A detailed description can be found at http://goo.gl/alfsQ.