What I understood from the film's message is that people such as Jesse Jackson and Al Sharpton don't appeal to the mainstream public because they assume all white people are racist unless they agree to give them something -- much like when Jesse Jackson and Al Sharpton shake down businesses to avoid allegations that they are somehow racist.
Obama, on the other hand, approached the public very differently -- with a kumbaya, "we're all in this together," non-threatening manner.
As Obama himself said in "Audacity of Hope," "I [Obama] serve as a blank screen on which people of vastly different political stripes project their own views."
Thanks!