> helped someone go... to the top of his field

Did it really? I seriously doubt it. Bill might be mistaken. To me it looks like just one of the cognitive biases: http://en.wikipedia.org/wiki/List_of_cognitive_biases

Unfortunately we cannot conduct an experiment of having two identical Bill Clinton, one of them read this book while another did not, then see they results.

But among more than 3 million of book readers, how many of them have something as close to Bill Clinton's achievements?