Our Brand is Crisis (2016)

Sandra Bullock does a good job of playing the under reacting political strategist, the one who does what it takes to win, even though she has earned the reputation of "Calamity Jane" because campaigns have crumbled at her feet.  Billy Bob Thorton plays the other side of the political strategist, the guy who tries to out creep the opposition, get under their skin and use their revealed weakness in that situation against them.  He slept with Jane in a previous campaign, and he thinks that he is permanently able to pull her strings.  She is not so sure that he can't but she wants to believe that she can resist him.
They come head to head in a campaign in Bolivia, where he is backing the front runner and she is for the corporate candidate.  She does a good job heading her opponent off at the pass and standing up to her candidate, who is stubborn as well.  But in the end she is not happy with the outcome and she stays to work with the opposition.