FBI says suspect in New Orleans attack inspired by ISIS

Yesterday in New Orleans, a pickup truck plowed through a crowd celebrating New Year's Day. Over a dozen people were killed and about twice as many were injured. The FBI said the suspect posted several videos on social media shortly before the attack saying he was inspired by ISIS. Given all this, The World's Host Marco Werman spoke to Aaron Zelin, a senior fellow at the Washington Institute who has monitored the group's activities, and who joined the show from Washington.