For the record, African American vote percentages from several past elections:
1984 Walter Mondale 90% // Ronald Reagan 9%
1988 Michael Dukakis 90% // George H.W. Bush 10%
1992 Bill Clinton 83% // George H.W. Bush 10%
1996 Bill Clinton 84% // Bob Dole 12%
2000 Al Gore 90% // George W. Bush 9%
Hell Al Gore got 90% of the black vote and he's about the whitest robot guy out there!
So Obama didn't get 93% of the black vote because he's black, he got it because he's a Democrat, which is the point several people were making.
The question you should be asking is why do Republicans policies make blacks, Latinos, women, gays and, well, anyone that's not an older white guy, want to vote for the Dems?