Senator Joseph McCarthy hired Cohn in 1953 as Chief Counsel for the Senate Permanent Subcommittee on Investigations. McCarthy relied heavily on Cohn—for contacts, information, ideas, and political advice.
Learn more about MCCARTHY, including where to watch the documentary: https://www.pbs.org/wgbh/americanexperience/features/mccarthy-roy-cohn-chief-counsel/