http://www.econtalk.org/archives/2017/05/cass_sunstein_o.html
"Confidence, unity, and extremism:" Cass Sunstein, co-author of "Nudge" and former Obama administration official, argues that these three factors have led progressives to silence conservative voices. Part of a fascinating EconTalk podcast about his new book, "#Republic, Divided Democracy in the Age of Social Media."