Racial Divide?

Here's an interesting political map about Obama's and McCain's voters, when divided by race:

http://www.fivethirtyeight.com/2009/03/how-did-white-people-vote.html

I enjoyed reading the comments. One comment pointed out that the map lacks a control. Without comparing the Obama/McCain map with the Kerry/Bush election, one can't reasonable conclude anything significant. Chances are, the maps might be similar for both elections, meaning there was no racial pattern in the 2008 election.