James Burnham was an American popular political theorist, best known for his influential work The Managerial Revolution, published in 1941. Burnham was a radical activist in the 1930s and an important factional leader of the American Trotskyist movement. In later years, as his thinking developed, he left Marxism and produced his seminal work The Managerial Revolution. He later turned to conservatism and served as a public intellectual of the conservative movement. He also wrote regularly for the conservative publication National Review on a variety of topics.