Horowitz earned a Bachelor's degree from Columbia University in 1959 and a Master's degree from the University of California at Berkeley in 1961. Horowitz quickly became a leader of the New Left. During the '60s, Horowitz edited Ramparts magazine, an influential left-wing journal.

In the 1970s, dissatisfied with the tragic consequences of radical politics in America and abroad, Horowitz withdrew from politics. He and his partner Peter Collier then co-authored a series of bestselling biographies of prominent American families: "The Rockefellers: An American Dynasty" (1976), "The Kennedys: An American Drama" (1985), "The Fords: An American Epic" (1987) and "The Roosevelts: An American Saga" (1994). For these works, the Los Angeles Times called Horowitz and Collier "the premier chroniclers of American dynastic tragedy." In 1978 Horowitz was honored with a Guggenheim Fellowship, and in 1990 he received the Teach Freedom Award from former President Ronald Regan.

During the '80s, Horowitz's second thoughts about politics crystallized. In their 1989 book, "Destructive Generation: Second Thoughts About the Sixties," Horowitz and Collier chronicled the legacy of the New Left and its effects on American politics and culture. Horowitz's political journey is recounted in his autobiography, "Radical Son," which will be published by the Free Press in February 1997. Author George Gilder has called "Radical Son" "the first great American autobiography of his generation."

In 1988, Horowitz created the Center for the Study of Popular Culture. The Center boasts 40,000-plus members, and publishes four magazines, including Heterodoxy, a monthly focusing on "political correctness and other follies."

One of Horowitz's current concerns is bringing new voices to Hollywood. In 1996 he and the Center held a daylong conference at Paramount Studios called Images of Ourselves, which featured Sen. Sam Nunn and William Bennett and brought together the best and the brightest from Washington and Hollywood. In the words of Los Angeles magazine, holding it "would have been unthinkable several years ago." David Horowitz has spoken at over 60 colleges and universities. He has appeared on "Nightline," "Crossfire," "Today," "Good Morning America" and "The CBS Morning News," and gives hundreds of interviews yearly on talk radio.