Political scientist Lilliana Mason of the University Maryland and author of Uncivil Agreement talks about the book with EconTalk host Russ Roberts. Mason argues that political partisanship has become stronger in America in recent years because it aligns with other forms of community and identity. People are associating primarily with people who share their political views in their other social activities outside of politics. As a result, they encounter fewer people from the other side. The intensity of partisanship can even overcome ideology as partisans change their policy positions in their eagerness to be on the winning side. The conversation closes with a discussion of what might be done to improve political discourse in America.