Jonathan Demme is staying in the politically correct mode. His TriStar drama “Philadelphia” is already being touted as one of the films to beat come Oscar time.Now, sources say, the director will follow up the project with the screen adaptation of the Pulitzer Prize-winning book “Parting the Waters,” Taylor Branch’s account of the civil rights movement under Dr. Martin Luther King. Though the book is fact-based, the movie will focus on a fictionalized family, intertwined with actual events during the movement. The script was written by Anna Hamilton Phelan. A source close to Demme said the director hasn’t quite committed, but is enthusiastic about the material.