Hull was first elected (as a Republican) to the Seventy-first Congress in 1928. He represented Wisconsin's 7th congressional district. He was an unsuccessful candidate for renomination in 1930 and an unsuccessful independent candidate in 1932. In 1934, Hull was once again elected to the House of Representatives this time as part of the Seventy-fourth Congress. He was elected as a member of the Progressive Party and represented Wisconsin's 9th congressional district. He was reelected to this post for the succeeding nine congresses, as a member of the Progressive Party for the first six and after the disbanding of the Wisconsin Progressive Party, as a Republican to the other four, serving continuously from January 3, 1935, until his death from pulmonary complications following surgery in La Crosse, Wisconsin on May 17, 1953.[2]