John Hechinger, senior editor for Bloomberg News, two-time winner of the George Polk Award for his reporting on education, on his book “True Gentlemen.” Hechinger investigates the fraternity culture with unusual access to Sigma Alpha Epsilon. Hechinger recently wrote an op-ed essay in the New York Times reflecting on the death of LSU pledge Max Gruver of Phi Delta Theta.   Don Weinell talks about bicycling the Oregon Trail from the Missouri River to Oregon City over five summers.   Barbara Radnofsky on “A Citizen’s Guide to Impeachment.” Her book details 19 cases of impeachment proceedings in U.S. history.