I've had this book in my collection for over 30 years now, so what I read was the Third Edition. I don't believe it mattered or made any difference in how I feel about it. The book reads like a text book; it is almost absolutely academic. As much as I love history, and appreciate the historical information and anecdotes this book provides, it is not enough to overcome the plodding pace, the pseudo-science, or the author's anti-conservative bias. How do I know it's bias? When you can make a book which was updated in the 1990's somehow make Woodrow Wilson appear to be both more patriotic AND a better leader than Ronald Reagan, it is author bias. That simply cannot happen organically, unless the reader is completely ignorant of facts and history, and is bent toward "progressive liberalism" himself, to the degree that he will accept anything that denounces pro-right think as good and right and true. What's worse for me, though, is that it took me nearly 2 months to slog through this volume (there were stretches where I simply could not make myself pick the thing up for days at a time!), and in the end I realized that not only is the book invalid due to its bias, but it also simply serves no purpose!! It does NOT tell us how to predict how a president will behave while in office. And in today's digital age where any candidate's life and politically history are available nearly instantly, in print and video formats, we don't need a predictor -- the candidates tell us and show us all exactly who they are and how they can be expected to behave or misbehave. We all knew Obama was going to a socialist, globalist sycophant who put America's interests at the end of the list. We all knew Biden was going to be ineffective, dishonest and disingenuous, based on his nearly 50 years in the Senate, his 8 years as VPOTUS, and his two prior failed bids to become POTUS (although I did not expect his faculties to erode so badly before his first term ended). Everyone knew Trump was going to be a wild card, although I doubt anyone would have predicted his successes because no one gave him any credit for being able to navigate the political storms. He was seen as a reality TV braggart loudmouth, uncouth, dirty rich (as opposed to Biden's rich), non-Establishment, and clueless. This book certainly would never have been able to predict his performance as POTUS!! And that's my point: this book is either obsolete or useless; the candidate's character can either be predicted based on a life made public by today's social media and technology, or the candidate is so completely erratic and spontaneous that it is impossible to predict what he will do in 4 years in office. Perhaps there was a once a time when this book could have proved useful, but if it existed, that time has passed.