A noted radio and stage performer, Mercedes McCambridge won an Oscar for her screen debut as the political hatchet woman in "All the King's Men" (1949) but subsequently made only occasional film appearances. An intense actress with piercing dark eyes and a strong, resonant voice, she specialized in forceful or domineering roles and was not afraid to play the unsympathetic role of Joan Crawford's insanely jealous and vindictive nemesis in Nicholas Ray's flamboyantly psychological Western, "Johnny Guitar" (1954). She earned a second Academy Award nomination as Rock Hudson's headstrong older sister in "Giant" (1956) and later played Elizabeth Taylor's mother in "Suddenly, Last Summer" (1959). McCambridge also provided the memorable voice-over for the demon-child in "The Exorcist" (1973). A recovered alcoholic, she has served as honorary chair of the Alcoholism Information Month and has appeared before the Senate committee on Alcoholism and Narcotics.