Mark K. Updegrove is the director of the Lyndon Baines Johnson Presidential Library and Museum in Austin, Texas, and the author of Baptism by Fire: Eight Presidents Who took Office in Times of Crisis and Second Acts: Presidential Lives and Legacies After the White House . A sought-after commentator on matters relating to politics and the presidency, he has appeared on ABC News, CBS News, CNN, Fox News, NPR, NBC News, and PBS.