Democrats want to keep Blacks voting solid Democrat (they are their most loyal group).
Primarying Obama will weaken that grip, possibly forever, for Democrats. Many Blacks will feel betrayed.
Therefore, Dems can’t primary Obama out of fear of losing the Black vote.
Well, probably true. However, blacks should realize the true ‘DEMOCRAT Politician’ for what it is. THEY are steadfastly working to replace this loyal 12-15% of the population (blacks) with Hispanics (both legal and illegal). With this sector secured, the 12-15% won’t matter.