Hmm...Let's see. By that logic, Stalin had marxist credentials (seeing as he was 'chairman' of a communist nation) and he slaughtered millions? Same goes for Mao et al.
Alan Greenspan was associated with Ayn Rand in the 60's before he became financial advisor to Nixon. Just because he was associated with Objectivists, does not mean he is one. Nor is he the "spokesman" of laissez-faire capitalism. He is about as much a spokesman for laissez-faire capitalism as Stalin is for communism.