Margaret's core story is about a bratty high schooler, Lisa Cohen (Anna Paquin), increasingly troubled by her feelings of responsibility in the death of a woman (Allison Janney) who's hit by a bus because its driver (Mark Ruffalo) is distracted by Lisa waving to him. The setup is similar to that of Kenneth Longergan's prior You Can Count on Me, which also begins with an accidental death and explores the way it affects those close to it. But with Margaret, Lonergan breaks away from his debut film's neat and balanced approach, employing a formal style that seems to mirror its characters' zig-zagging emotions, unafraid to let his narrative grow sideways, leaving in scenes that feel broken off, subplots that could have been cut, and numerous punctuating shots of random buildings and streets. This is a film that's more interested in the emotions its characters' seem subordinate to—the exposed nerves that John Cassavetes was so brilliant at finding in his characters. Unlike Cassavetes, who could direct a movie without a screenplay, Lonergan relies on his writing to carry his direction through, so Paquin should be lauded for the way her brazen performance—such as the manner in which she throws herself into every scene, even those that make Lisa a strident and difficult character to like—rounds out Lonergan's efforts, bringing depth to his words.
Many have complained that Margaret feels unfinished (Longergan's preferred cut ran three hours) and shapeless (the film had been mired by years of lawsuits regarding a final edit). But these imperfections work in the sense that they rhyme with the agitation and sense of dislocation the characters feel; they allow unbounded emotions—which at times flow through the characters' world as strongly as the electricity that powers the film's New York City setting—to feel recognizably human, alive, and free-forming instead of sculpted and practiced. In all its nakedness and ugliness, Lisa's evolving self-awareness throughout the film's 149-minute running time, from the losing of her virginity to the way her guilt for lying to the police about the accident eats away at her and propels her to clumsily try to reconcile the situation, is conveyed with striking keenness.
Margaret novelistically accumulates brief interactions between characters, their moment-to-moment emotions, and other small details that fill out and color Lisa's world to a degree that's unwieldy but far-reaching, covering the ripples as they spread outward from the day Lisa held the bloody, dying woman in the street. Although they all must share the same space, it often seems as if the characters in the film aren't capable of mutual understanding—and so they become a kind of microcosm for how Lonergan sees America in the larger world. Lisa nearly finds a connection with the dead woman's best friend, Emily (Jeannie Berlin), a surrogate of sorts for her own tired and busy single mother (J. Smith-Cameron), but soon realizes that even their shared interest in seeking punishment for the bus driver ends where the lawsuit they filed can only guarantee monetary compensation for a distant relative. If Margaret focuses on how the repercussions of one accidental death spread through Lisa to those only connected to it by degrees, it's also pointing to the way the city's post-9/11 psyche has affected everyone, which makes the film's sudden release seem appropriately timed to coincide with 9/11's 10-year anniversary.