Madeleine Elizabeth Sloane (Jessica Chastain) is the most powerful lobbyist in DC. She brings to the table a winning attitude and a ruthlessness that make her the best at what she does. She fights for things she believes in; that's how she sleeps at night, she says. When the head of the gun PAC wants to engage the services of the firm she works for, and hers in particular, Elizabeth expresses with conviction that she is pro gun control. No, she doesn't know any victim of guns; that is something she firmly believes in. Elizabeth is then approached by the CEO (Mark Strong) of a small firm, to win Senators to vote in favor of a bill that would impose universal background checks for arms buying. She is convinced that that may be the biggest win of her career, or her downfall... if her rivals have any saying in it.
Miss Sloane, directed by John Madden, is probably the gutsiest movie of 2016, but I bet not many people have heard of it. It would have had a wider audience had it not been on the thorny debate of gun control and universal background checks to delay, if perhaps not prevent, criminals and would-be criminals from arming themselves legally. Both sides are debated with passion, but no definitive conclusion is reached in the movie if only because we, Americans, haven't reached a consensus on the issue, thanks, partly, to the immensely powerful influence of the pro-gun lobby.
In the leading role is Jessica Chastain in, what is in my opinion, the best performance of her career. That is saying something because her relatively short career is hallmarked by outstanding performances in even more impressive movies, such as The Tree of Life, The Help, The Debt, The Disappearance of Eleanor Rigby (Her, Him, Them), Zero Dark Thirty—for which she was nominated to the Oscars as Best Actress in a Leading Role, which she should have won by a long shot—, Interstellar, Crimson Peak, and the most recent and commercially successful The Martian.