Credited with being a central founder of the neoconservatism, Kristol was often quoted as saying the political movement was for liberals who had been "mugged by reality." His theories centered around the limits of public interest and welfare programs of the 1960's and 19070's, which he claimed only worked in theory, not in practicality. In 1965, he co-founded the magazine "The Public Interest" in which he discussed these beliefs and began the neoconservative movement. Though raised as a liberal Democrat, as an adult Kristol switched to the Republican Party. He believed his neoconservative theories and religious faith were an integral part of that association's values. Kristol died on September 18, 2009 at the age of 89.