Ali Soufan on white nationalism: “What happened Wednesday is not the end, it’s the beginning”

Ali Soufan, hostage negotiator and author of ‘The Black Banners’, and is also founder of The Soufan Center, a non-profit that has become the leader in studying how domestic extremist groups operate and assessing their threat level. He tells Ali Velshi that the rise of white nationalism across the United States is “an existential threat” and that those involved in the insurrection must be held accountable to show the world “America is bigger than a demagogue, stronger than a mob.”