I'd say there are any number of issues that could be used to refute the contention that Democrats "don't do shit" for black people, but its certainly off when the first thing a Democratic House did was pass legislation to counter Republican efforts to disenfranchise black voters.
One issue where Democrats and the interests of black people are not aligned are Charter Schools. But opposition to them isn't across the board, and where it does exist its an attempt to protect traditional public schools which certainly have done more than "shit" for the African American community.
All that said, I suspect LarryBnDC (DC...its Democrats that support its largely African American citizens getting seats in congress) was exaggerating for effect.