For years, bestselling author David M. Rubenstein has distilled the contours of American democracy through conversations with noted leaders and historians. In his recent book The Highest Calling: Conversations on the American Presidency, he offers an enlightening overview of arguably the single most important position in the world - the American presidency - through dialogues with our nation’s presidents and the historians who study them. Rubenstein, the cofounder and cochairman of The Carlyle Group, one of the world’s largest and most successful private equity firms, discusses the book with JFK Library Foundation Board Member Christine Heenan, chief communications officer and executive partner at biotech venture company Flagship Pioneering.