One of the most interesting observations from the original Post article is that DC's black population has actually been growing for the first time in decades.

the District, which has been losing African Americans to the suburbs for decades, the census estimated the black population rose by 2,100 people last year. The biggest gains for blacks were in people ages 20 to 34 and older than 55. But the city gained so many whites, Asians and Hispanics in the same time frame — mostly in the same age groups — that African Americans slipped below the 50 percent mark in the District.

http://wapo.st/MY2p3R