This tall, burly, likable actor has made his mark in a variety of comic and dramatic roles, finding shadings and character nuances in even the most unsympathetic parts. Quaid's range is evident in strong starring roles (as a young, flamboyant President Lyndon Johnson in "LBJ: The Early Years", a 1987 TV-movie) and in small unflattering roles (a crass car racing promoter in "Days of Thunder", 1990).While still a college drama student, Quaid was discovered by filmmaker Peter Bogdanovich and made his screen debut in the director's first feature, "Targets" (1968). He followed with a role in the