Difficult to watch and hard to look away from, this emotional traffic wreck of a movie divided viewers and critics and failed to earn a popular audience despite an Oscar nod for Mare Winningham in the title role. Some felt Jennifer Jason Leigh's performance too mannered, but even her detractors have to admit that the actress is fearless. Whether high on smack, sullenly mooching off her family, or ruining a bar mitzvah with her raspy yelping, Leigh's Sadie lurches through life, a black hole of need, determined to become the one thing her lack of ability won't let her. Plenty of the actress's scenes are nakedly painful to watch, but the most harrowing is the sequence in which she takes the stage to croak a Van Morrison classic triumphantly and interminably, unaware of her own talentlessness and of the burning eyes of the sister she's embarrassing. Georgia herself is a serene, satisfied mother and wife, proficient and popular, but lacking in passion. Winningham's performance is therefore more measured, less showy than Leigh's, but it's just as impressive for its restraint and range. A who's who of indie talent, including Max Perlich and John C. Reilly, fleshes out the first-rate cast. But the entire effort hinges on the screenplay, written by Leigh's mother, Barbara Turner. Deliberate and disturbing, it's a powerful examination of oft-neglected grown-up sibling dynamics. Director Ulu Grosbard presents the story simply, but that's all he needs to do, and for those who can stomach the emotional carnage, the film's an engrossing success.