From NY Times:
"Yet Mrs. Clinton has also benefited from the strong support of white voters in many states, including some who have said that race was a factor in their support."

From AP:

Only three in 10 whites who said race was a factor said they would vote for Obama should he oppose McCain in November. Four in 10 said they would back McCain, while the rest said they wouldn't vote.

Ahhh... Good ol' racism! What year is this again?