Gary Hart is a professor, lawyer, public servant, author and commentator from the state of Colorado. He formerly served as a Democratic U.S. Senator representing Colorado , and ran in the U.S. presidential elections in 1984 and again in 1988, when he was considered a frontrunner for the Democratic nomination until withdrawing from the race. Since retiring from the Senate, he has emerged as a consultant on national security, and continues to speak on a wide range of issues, including the environment and homeland security. In 2001, he earned a doctorate in philosophy at Oxford. In 2006, Hart accepted an endowed professorship at the University of Colorado at Denver. He also serves as Chairman for Council for a Livable World. He has written or co-authored numerous books and articles, including four novels, two under the pen name John Blackthorn.