 Starr worked as a partner at Kirkland & Ellis, specializing in litigation.He was one of the lead attorneys in a class-action lawsuit filed by a coalition of liberal and conservative groups (including the American Civil Liberties Union and the National Rifle Association) against the regulations created by the Bipartisan Campaign Reform Act of 2002, known informally as McCain-Feingold Act.In the case, Starr argued that the law was an unconstitutional abridgment of free speech.