Playing President by Robert Scheer

This was excellent; it makes me want to read the book.
Truthdig - Reports - Playing President: "Playing president is not a book title selected casually, but a distilled opinion gleaned over forty years of journalism, covering our most important democratic exercise. After decades spent interviewing dozens of leading presidential candidates, including those who ended up in the highest office, I came to the conclusion that the process endured in obtaining electoral power tends to be the controlling influence on the candidate�s behavior once in office. "