Cool comment from Harry:
I can see how this is surprising if, as is the case for most Americans, somone is just getting to know Obama and isn't from his home base in the Midwest/Illinois (Land of Lincoln), where he won over (first) a racially integrated neighborhood on the South Side of Chicago (Hyde Park) as a State Senator in '96, then won a U.S. Senate seat for Illinois in 2002, most of which outside of Chicago is rural and white, as are of course large parts of Chicago. Of course it helped that the Republican Party has collapsed in Illinois, the way it has nationally, and in 2002 Obama was up against a Fundamentalist wing-nut -- who was also black.
In the SuperTuesday Illinois primary, Obama swept the state outside of Chicago, and the majority of Democratic primary voters were women. Something similar played out throughout the Midwest in Iowa, Wisconsin, Minnesota. The media has paid no attention to the history here: despite anti-black racism that has roots everywhere, these were all Northern Free states at the time of the Civil War, and had active lines of the Underground Railroad leading up to Canada. Appalachia and the South have different stories, and we've seen how that's affected the campaign.
If anything, more whites -- to the extent that that "white" is a static category of analysis itself (at different times it has not included Jews, Catholics, Italians, Poles, the poor, rural folks, etc.) -- should be surprised that so many blacks (another fluid category) voted for him. It was only relatively late in the game that so many left the Clinton camp. And Obama himself has taken conscious decisions to beef up his repertoire of conventionally black culture traits as he outlines himself in his writings.
America may not be post-racial, but it IS multi-racial, and so is Obama, and that's why he is such a beacon of hope to so many, especially the young, the urban, and the educated, and independent.