"A Night of Camp David" is a rather remarkable novel written by Fletcher Knebel in 1965. He was also the co-author of "Seven Days in May." Both are still in publication and Camp David was on the NY Times Best Seller List for 18 weeks.
Without giving away the plot completely, it is the story of a young ambitious senator from Iowa who is summoned to Camp David to meet with his charismatic populist president who wants him to replace the current vice president, mired in scandal, as his running mate for his second term. The conversation gradually slips into a world where the president rants about his enemies and other issues. He erratically expresses his desire to develop a closer relationship between the United States and the USSR, and wants to cut ties with US allies in Europe. The president is convinced the news media and much of the party leadership are conspiring against him. The senator gradually concludes the president is mentally ill and dangerously paranoid.
To remind, this book was written in 1965. It is an excellent read that obviously has held up rather well.