Clooney told The Cincinnati Enquirer that he decided to film the movie in his hometown of Cincinnati because he thought it'd be fun and he knows the town well.
The actor also served as director for the movie. He stars as fictional presidential candidate and Pennsylvania Gov. Mike Morris. Co-star Ryan Gosling plays the governor's idealistic press secretary who learns quickly about dirty politics.
Clooney also told the newspaper that the movie was inspired by his father Nick Clooney's unsuccessful 2004 run for Kentucky's 4th Congressional District.
The actor said many of his character's political views are derived from his father's work as a columnist for the now-defunct newspaper The Cincinnati Post.
The Associated Press contributed to this report.