Steve Coll, President-New America Foundation / Staff Writer-The New Yorker / Author of the new book, "Private Empire: Exxon Mobile and American Power" joins Thom Hartmann. Exxon Mobil is the largest and most powerful private corporation in the United States - and yet - very little is actually known about how the company operates. How does this corporate giant really function - and how much control does it have over lawmakers in Washington? We'll pose those questions and more to Steve Coll in tonight's Conversations with Great Minds.