clinical assessments. they're not meant to be judgments. they're just how doctors speak. when you bring it to the political realm, it's felt to be purely subjective, just an attack. but if there were a process by which, as we see candidates get older and older, there were an objective evaluation by neurologists, psychologists, and the information was shared in a transparent manner, and voters, the american public, the cabinet can make of it what they will, but they have the information, it'd inform the process. >> you have been following the trumps and particularly the president for several years. how do these descriptions strike you? when was the last time you interacted with him? >> i've been following him more than several years. more like 25 years, when i first started interviewing him for my book. it was about him, his father, his grandfather. really looking at the whole family culture, the background of this family over a century. the striking thing about him during the course of my interviews for the book was