20. John Donohue: “I'm Frequently Called a Treasonous Enemy of the Constitution.”

He’s a law professor with a Ph.D. in economics and a tendency for getting into fervid academic debates. Over 20 years ago, he and Steve began studying the impact of legalized abortion on crime. John and Steve talk about guns, the death penalty, the heat they took from their joint research,  and why it’s frustratingly difficult to prove truth in the social sciences.