If there's one thing that people across the political spectrum can agree on, it's a sense of discontent with the current state of American politics. This week, we explore the origins of that discontent and why it's damaging to democracy. Our guest is Matthew Rhodes-Purdy, an assistant professor of political science at Clemson University and one of the authors of The Age of Discontent: Populism, Extremism, and Conspiracy Theories in Contemporary Democracies.Rhodes-Purdy and his co-authors argue that the most successful populist and extremist movements of the past 20 years have focused largely on cultural grievances, rather than on economic discontent. The book outlines what they describe as  the troubling implications of discontent on the long-term compatibility of liberal democracy and free-market neoliberalism. Looking at case studies from around the world, the authors imply that democratic states must renew their commitment to social regulation of markets and to serve as conduits for citizen voice for  democracy and market economies are to survive.