An African American male in showbusiness doing whatever the white man says to become more successful. See also: Aunt Jemima, Uncle Tom.
While derogatory in modern use, the term refers to succesful and groundbreaking 1920's dancer/actor William Robinson, who was nicknamed Bojangles in his vaudeville days. It means no disrespect to the talent and hard work Mr. Robinson put forth to become one of the most important entertainers of all time.
If you're on the UPN network, you're a Mr. Bojangles.