Last week, a Los Angeles theater owner canceled a planned screening of D.w. Griffith’s 1915 movie “The Birth of a Nation” after civil rights groups promised protests. But the movie ought to be screened, not suppressed, argues Renée Graham. “Much like Leni Riefenstahl’s 1934 Nazi propaganda documentary ‘Triumph of the Will,’ an equally acclaimed, equally troubling film, ‘The Birth of a Nation’ is a painful totem to our own intolerance and to how such ill feelings still vex us today.”