Robert M. La Follette Jr.

Robert Marion "Young Bob" La Follette Jr. (February 6, 1895 – February 24, 1953) was an American politician. He was a U.S. Senator from Wisconsin from 1925 to 1947. He was a son of U.S. Representative, U.S. Senator and Wisconsin Governor Robert M. La Follette Sr., and father of Wisconsin Attorney General Bronson La Follette. 
He was a co-founder of the Progressive Party. He lost to Joseph McCarthy in 1946.