http://pewresearch.org/pubs/1023/exit-poll-analysis-2008
"He also gained seven points among African American voters (95% vs. 88% for Kerry), and managed to slightly improve on Kerry's share of the white vote (43% vs. 41% for Kerry)."
http://jonathantilove.com/dems-white-vote/
"In the virtual tie of the 2000 election, Gore won 42 percent of the white vote and Bush, 53 percent."
So whites supported Obama more strongly than they have the last two Democratic candidates.
In 1996, Clinton got 48% of the white vote v. Bush's 44%. And that was a good year for the Democrats.
http://bdeco.tripod.com/presidentialregions/characteristics.html
On edit: I think the important split is not on racial issues (albeit those are given most coverage in the media), but by economic and "cultural" issues. I don't like the national review people, but I think they're right in saying that the Democrats have been losing the white working class.
and on second edit, I add this about cultural issues:
"In Ohio, according to exit polls conducted by the National Election Pool,Bush won 16 percent of the black vote, up from 9 percent in 2000....With those additional 110,000 black votes, Bositis said, the identity of the next president might still be in doubt.
Bush scored a similar gain with black voters in the battleground states of Florida, where the 13 percent contributed to his comfortable victory, and in Pennsylvania, where Democrats were able to absorb the 16 percent and still win.
The lessons for both parties are profound.
For Republicans, it demonstrates that even a small success with black voters can pay huge dividends, and that their opening to the black community is through the church door and an appeal to a strong strain of conservative Christian values."
http://jonathantilove.com/bush-black-vote/