By Sandra Mitchell Films in the Blaxploitation genre can have unusual or common themes central to their plots. But often, and with the best of them, they usually nod at issues that are traditional elements of African American societies. These are different from usual exploitation films, which tend to be very derogatory about its subjects. There is one film that might have risen above the rest, as differentiated by the common run of movies here. The film in question is Trick Baby, released in 1972, with a story taken from the novel of a famous...