I would say the main reason why we have more racists blacks in America today is Slavery, and continued white discrimination of blacks, with regards to employment, housing, how blacks are treated in the Judicial system here in America.
There are many black churches, that you won't see any whites going to, there are all black upper class neighborhoods in Atlanta GA, that whites can't even move into, the list goes on and on.
And it seems to be getting worse, not better. Blacks self segregate more so than whites.
And as the economy gets worse, this black racism is blaiming whites for the economic downturn.