A Chicago mayoral primary fueled by the issue of crime ends up with the incumbent’s ouster and an April runoff between two Democrats with opposing views on education – one espousing school choice, and the other backed by a powerful teachers’ union. Michael Hartney, a Hoover Institution fellow and author of How Policies Make Interest Groups: Governments, Unions, and American Education, discusses the oversized influence of teachers unions in policy-making, elections, and interest-group politics.