In both 2008 and 2012, there were distinct geographic areas that bucked the nationwide trend toward one party. In both cases, they're legacies of America's racial divisions. In 2012 (shown at left from the neat animated New York Times map of yesterday's vote) most of the country voted more Republican except for a strip of blue that runs through the Deep South in Mississippi, Alabama, Georgia, and South Carolina where many rural black people live.

 

 

In the 2008 presidential race (at right) most of the country voted more Democratic, except for a red Appalachian spine that ran from West Virginia through Tennessee and Kentucky into Arkansas which is the part of the South where fewer black people live and Obama did not do well running basically unopposed in this year's Democratic primary.