bivariate choropleth map

A bivariate choropleth map portrays two separate trends simultaneously. The main objective of a bivariate map is to find a simple method for accurately and graphically illustrating the relationship between two spatially distributed variables. This is an example of the 2008 presidental election. It shows the canidate each state voted for and the electoral college votes. 

http://rvclearance.com/index.php?option=com_content&view=article&id=93%3Awhat-do-the-2008-election-results-mean-to-the-economy-and-the-rv-industry&catid=3%3Anewsflash&Itemid=50