One Heartbeat Away: Presidential Disability and Succession

Senator Birch Bayh is the James Madison of the 25th Amendment and this is a good account of the process of its ratification from the days of the JFK assassination to a summary blow by blow account of the ratification in the states. The whole book can be downloaded for free. A briefer summary via 1980s commission he was involved in is here. See also here. He actually just died last year. Part of the lesson is the value of compromise and deciding upon some ground rules, which was never addressed even though an earlier incapacity provision in theory might have served as an opener. Will the last section ever be put in operation?