Well, I sort of doubt it, but maybe there's no "excitement" in this black community about the Big Zero because the Big Zero isn't authentically African-American.
The Big Zero's only half black, and not the same black of African derivation of most African-Americans.
Also, the Big Zero had an upbringing far removed from the experiences of blacks in America.
If the Democrats wanted an authentic black candidate for the presidency, they had a whole stable to choose from; everybody from Congressmen John Lewis (D-Georgia) to Floyd Flake (D-New York) to Melvin Watts (D-North Carolina) to Jesse Jackson Jr. (D-Illinois) to William Jefferson (D-Louisiana).
Good or bad, all the above guys know what it's been like, being black in America.
It's sort of as if I were to run as a deaf candidate--which I couldn't, because I've enjoyed some advantages most deaf people never did.