Obama's main asset is not blacks - it's guilty whites, and in this regard he's just like Deval Patrick and Harold Ford, junior.
All three are nontraditional "black" politicians swept into office (or nearly missing it, in Ford's case) by white votes.
Hillary needs to overcome the fact that her "never vote for" numbers are too high. She cannot do this with any white VP nominee.
So he would bring in the “guilty whites” and Hillary doesn’t already own them? Partial point granted. Not sure it’s significant.
Mrs. Bill Clinton already would get this vote because she's a woman.