Daryl Johnson, former senior analyst at the Department of Homeland Security and author of “Hateland: A Long Hard Look at America’s Extremist Heart” and Jason Blazakis, Director of the Center on Terrorism, Extremism, and Counterterrorism at the Middlebury Institute of International studies and senior fellow at the Soufan Center, discuss with host Carol Castiel the roots of domestic terrorism, why it poses a major threat to US democracy and national security and how to combat it.