Once a prominent supporter of Marxism and a member of the New Left in the 1960s, Horowitz later rejected Leftism and is now on the right of the political spectrum. David Horowitz is an American conservative writer and activist. He is a founder of the David Horowitz Freedom Center (formerly the Center for the Study of Popular Culture), and has served as president of that organization for many years. He is the editor of the conservative website FrontPage Magazine, and his writings can also be read on prominent news sites and publications, including the conservative magazine NewsMax. He founded the activist group Students for Academic Freedom and is affiliated with Campus Watch.
His parents, Phil and Blanche Horowitz, were school teachers. Horowitz attended Columbia University and later the University of California, Berkeley, where he received a master’s degree in English literature.

His parents were long-standing members of the Communist Party. While still identifying as a Marxist, Horowitz, along with many other left wing figures of his generation, sought to distance himself from the Soviet Union. Horowitz was employed during the 1960s as a political aide to Bertrand Russell. Horowitz at this time was a close friend and associate of Marxist historian Isaac Deutscher. Horowitz wrote a biography of Deutscher in 1971.