Fear is an emotion, but it is one with a long history in both political theory and politics in the real world. In many versions of social contract theory, it is a fear of the state of nature that leads to government in the first place. From McCarthy to post-9/11 politics, fear has played a leading role in American public discourse. Ken and John examine fear as theme in politics and political philosophy with Corey Robin from the City University of New York, author of Fear: The History of a Political Idea.