90% of blacks vote Democratic regardless.
When the candidate is also black, it goes up to 95% or so.
Until that changes, they will continued to be ignored by the people they elect. The only way they will be listened to is if their voting habits change.
Republicans know that they vote 90% Democratic so they don't bother pandering to them. Why waste time trying to influence someone who you know won't be influenced?
Democrats also know that they vote 90% Democratic, so they don't waste their time on them either. They may give lip service, but once elected they go back to ignoring them.
All the money is spent on those in the middle, namely the ones who can actually be influenced by what you say.
Black unemployment remains nearly double that of white unemployment and that gap has remain unchanged during the Obama administration.
There are occasional murmurings in the black community about their disappointment with Obama, but most of those get shouted down the minute they open their mouths.