Following the death of U.S. Senator William J. Harris in 1932, Governor Russell defeated Congressman Charles R. Crisp to serve the remainder of Harris's term; he was elected on his own to serve a full term in 1936 and was subsequently re-elected in 1942, 1948, 1954, 1960, and 1966. During his long tenure in the Senate, Russell served as chairman of the Committee on Immigration (75th through 79th Congresses), the Committee on Manufactures (79th Congress), the Committee on Armed Services (82nd and 84th through 90th Congresses), and the Committee on Appropriations (91st Congress). As the senior senator, he became President pro tempore of the Senate during the 91st and 92nd Congresses.