Since her extraordinary breakout year in 2011, Jessica Chastain has been one of Hollywood's most in-demand actors, taking roles in high-profile and acclaimed fare. Now, Chastain gets to test her drawing power with her very first solo vehicle. Unlike even Zero Dark Thirty, Miss Sloane is marketed entirely on Chastain's name and image, which means she will be judged on the movie's commercial success or failure. Which isn't really fair because this is a talky drama about politics, a subject that almost never lights the box office on fire.

Chastain plays Elizabeth Sloane, an influential Washington, D.C. lobbyist, who at the film's opening is being subjected to a Congressional hearing. Sloane's ethics are in question and we come to see why, jumping back a few months to see her take extreme measures to perform her job. The movie mostly focuses on one specific bill that is being pushed to reduce gun purchase requirements. Sloane breaks out in laughter at the pitch, then takes her services to a competing agency, where they try to get enough support to shoot down the divisive legislation.

From novice screenwriter Jonathan Perera and seasoned British director John Madden (Shakespeare in Love), Miss Sloane fancies itself to be an Aaron Sorkin movie. But it doesn't have the cadence and impact of Sorkin's dialogue and the lines it feeds Chastain and her veteran supporting cast -- which includes such experienced actors as Mark Strong, John Lithgow, Michael Stuhlbarg (putting on a clunky accent), Sam Waterston, Gugu Mbatha-Raw, and Alison Pill -- are rarely as smart as they think they are. This dialogue-driven presentation avoids inertia and feeling stuffy. But it runs much too long and repeatedly gets heavy-handed as it turns its titular heroine into, alternately, a martyr, a sinner, a saint, and a genius.

Chastain serves the material as well as any living leading lady probably could, but even she can't make it sizzle like it should. The movie belabors and exaggerates everything, preaching about gun control reform and ethics long past the point where you might care. Much of it seems unbelievable, from Sloane's dependence on an old-fashioned escort service to the use of mechanically modified and pilotable cockroaches.

The timing of Miss Sloane suggests it has the potential to make waves in the awards race. But apart from some recognition that Chastain may trump up, which is as much a reflection of her gender's marginalization as of her performance, this is likely to be a non-starter there, as well as a commercial disappointment.