Two of the people under investigation by Robert Mueller — Roger Stone and Jerome Corsi — are conspiracy theorists who believe the deep state is trying to take over America. 'New Yorker' staff writer Jeffrey Toobin tells Terry Gross how Stone and Corsi came together to support Donald Trump during the 2016 presidential campaign, and why they matter to the Mueller investigation. "If there was contact between the Trump campaign, or even Trump himself, and WikiLeaks, it went through Corsi and Stone," Toobin says.