David Gergen is a well known and highly regarded American political consultant, a professor of public service and director of the Center for Public Leadership at the Harvard Kennedy School. In addition, he serves as a senior political analyst for CNN and regularly provides political commentary for CNN as well as other media. In the past, he has served as a White House advisor to four U.S. presidents: Nixon, Ford, Reagan and Clinton. He wrote about those experiences in his New York Times best-seller, Eyewitness to Power: The Essence of Leadership, Nixon to Clinton (2001). In the 1980s, he also served as chief editor of U.S. News & World Report, initiating his career in journalism. He is currently at work on a new book.