In the most recent primary, Pennsylvania, 62% of whites support Clinton with 38% supporting Obama.
However, 90% of blacks voted for Obama.
This has been the trend this entire election season. Nearly every primary, the black vote is predictable as sunrise. In many of the earlier primaries, the white vote was split between Clinton and Obama with Obama taking most of the black votes, consistently over 80%.
As for whites voting for Obama, you have states ranging from as low as 25% to 60% (with Utah had 55%; Georgia had 43%)..
Now, I know they're all white democrats and independents (in open primaries) who are far less racist than any republican so let's go ahead and set that aside. And, then, after a moment of pause... let's ask....who is it again that has the most trouble with voting for someone who is not of their own race?
Overall, it doesn't appear to be whites.
Identity politics. Gotta love it.
(Aside: Someone in a previous thread felt incensed that the term "blacks" was used to describe black people. As you can plainly see, this chart refers to white people as "whites." Don't remember who it was, but there you go.)