Is the author saying that only blacks can be "street whores", "ghetto thugs", "ghetto street trash" and only black women have abortions?
We know who the racist is now, don't we?
No, the author is saying that those play into predictable stereotypes of blacks, just like a lot of the unsupported allegations against Sarah Palin play into predictable stereotypes of poor rural whites. Assuming the worst of a person based on their race, ethnicity, sex, or class on the basis of negative stereotypes even when they aren't true is pretty much the core of bigotry.