Horowitz, a conservative activist and writer, used to be the publisher of Ramparts, a left-wing magazine published in the late 1960s. He eventually grew disillusioned with the New Left and became a conservative anti-communist. He later founded the Center for the Study of Popular Culture, a right-wing think tank. Horowitz is also a founder of the Second Thoughts Foundation, an organization of ex-radicals from the 1960s who have renounced their previous political beliefs. In his autobiography, Radical Son: A Generational Odyssey, Horowitz writes, "Socialism was a secular faith: I had been a believer, and I had been burned. I did not feel an opening in my soul for renewed risk. I had affection for the Old Testament God, and was invariably moved during the service by the connection I felt, through the ancient prayers, to ancestors who live millennia ago. But to God's actual existence, I remained stubbornly agnostic. If I believed in anything, it was the mystery itself." (p. 414) Horowitz used to attend a synagogue occasionally with his ex-wife, but he evidently stopped attending after his wife walked out on him.