Because the feral bastards copulating and populating them are not "normal" or "equal" human beings. Yet they are granted the vote, thus electing their "own" - while being subsidized by the productive citizens they prey upon.
In the entire world, it would be difficult to name a major city with a majority black population that is not dangerous, corrupt and overly dependent on outsiders to exist.
Obama is already proving he is NOT the exception to the rule.
‘Bread and Circuses’ is the cancer of democracy, the fatal disease for which there is no cure. Democracy often works beautifully at first. But once a state extends the franchise to every warm body, be he producer or parasite, that day marks the beginning of the end of the state. For when the Plebs discover that they can vote themselves bread and circuses without limit and that the productive members of the body politic cannot stop them, they will do so, until the state bleeds to death, or in its weakened condition the state succumbs to an invader - the barbarians enter Rome.... Mine was a lovely world till the parasites took over.
Robert Heinlein