Today on The Gist, Barton Swaim gives us a glimpse inside the world of a certain former governor of South Carolina. Swain's new book is called The Speechwriter. Plus, Dr. Jeffrey Lewis responds to lingering criticisms of the Iran nuclear deal. Lewis hosts Mike's favorite arms podcast, Arms Control Wonk. For the Spiel, advice for the last Republican on stage at Thursday night's Fox News presidential primary debates. Join Slate Plus! Members get bonus segments, exclusive member-only podcasts, and more. Sign up for a free trial today at slate.com/gistplus.

Learn more about your ad choices. Visit podcastchoices.com/adchoices