From Wikipedia:
Powell [Jr.] married three times. His first wife was nightclub entertainer Isabelle Washington (sister of actress Fredi Washington). Powell and his second wife, Hazel Scott Powell, had a son, Adam Clayton Powell III, who is a visiting professor at the Annenberg School of Communications at the University of Southern California. With his third wife, Yvette Diago Powell, Powell had a son, Adam Clayton Powell IV, who is a member of the New York State Assembly. Adam Clayton Powell III has a son, also called Adam Clayton Powell IV, who is a professor of engineering at the Massachusetts Institute of Technology. To distinguish the two Adam Clayton Powell IVs, they are known as the Hon Adam Clayton Powell IV and Professor Adam Clayton Powell IV.
(It sounds to me like brother III is old enough to be brother IV's father.)
good info... the fact that someone would endorse Al Sharpton is a bit creepy to start with.