"The most lethal and persistent terrorism-related threat to the homeland today." That's how US Homeland Security Secretary Alejandro Mayorkas has described domestic extremism. It's a mounting threat to democracy and security in Europe, too, and elsewhere as hardline views enter the mainstream. Susan Corke—Intelligence Project Director at the Southern Poverty Law Center—joins Greg and Jonathan to describe the fast-evolving threat and how to address it, together with Sasha Havlicek, a pioneer in combatting hate, conflict and extremism.