And here, too, is the woman who would bring the glory days down, Warhol’s wanna-be assassin Valerie Solanas (Lili Taylor), a self-described “butch dyke” and author of the man-hating “SCUM Manifesto.” “I Shot Andy Warhol” is her story, which proves, alas, more pathetic than illuminating. Taylor, one of the MVPs of the American independent movie, gives a droll, raging serio-comic performance, but even she can’t sustain our interest in a character (as written by Harron and Dan Minahan) whose delusional behavior ranges from crazy to crazier. Harron sets the stage expertly, but her lack of a point of view ultimately enervates the movie. The strongest emotion this stylish but water-treading film generates is voyeuristic nostalgia.