OPERATION CHAOS.
Barack will win the black districts overwhelmingly. Hillary will win the (bitter) rural districts. But the rural districts have usually four delegates. So unless Hillary gets above 62.5%, the delegates will be split 2-2. As long as Barack gets 12.5%, he'll get one of the four delegates. So even a blowout by Hillary won't yield many delegates. There are some state-wide allocated delegates, but on the CD allocated ones, she won't win that many.