Jesse Jackson is probably a little bitter about seeing a young guy who didn't go thru 'his' civil rights struggle ascend to the White House (Jackson failed to get anywhere near the kind of popular support Obama is when he campaigned).
I don't want to generalize, but when Black America listens to the old school leaders they get angry history lectures. When they listen to Obama they get excited about building a new future. Therein lies Obama's success where others have failed- drawing in the white vote as well.
Obama's mixed race parentage will serve him well in modern America, which is increasingly turning into a genuine melting pot. Race division has been replaced for the most part with economic class division being the primary ranking factor in how one stands in the USA.