Discussion question: Race in The Wire

I found the portrayal of race in The Wire interesting, in that I did not feel as though there really was a "portrayal" of race. If we look at the characters outside of the Towers and the drug-dealing industry, there seems to be an equal portrayal of Blacks and Whites in positions of power. The cops that are less than perfect (such as the scene in the second episode at the Towers) are both Black and White. In fact, Daniels and his wife are shown in a very nice house eating dinner by candlelight while McNulty is drunk in his car. Greggs is one of the best policemen on the case. So, race seems to be mostly salient within the Towers and the drug-dealing industry. On that level, however, I felt as though they were accurately portraying what it was like in Baltimore. Urban areas were mostly inhabited by Blacks and many of them probably did talk with those accents and engage in those activities. So that raises the question: does their choice of subject matter, that necessarily demands the depiction of Black characters in this manner, count as an negative portrayal of race?