@farmerman,
John McCain and I were in the same battalion at the Naval Academy, though he was several years ahead of me ( and repeated one year on an academic issue ). A good guy, but even then, a rebel with a hot temper and a willingness to hold a grudge. He was a well known figure in Naval Aviation, a pilot in VA-163 ( the "Saints") then led by another famous Naval Aviator, Bryan Compton. During deployments to the Tonkin Gulf on USS Oriskany, this squadron distinguished itself in combat ops over North Vietnam, and lost several pilots in the process, including then air wing commander Jim Stockdale, and a couple of years later, Lt, John McCain.
Interestingly, in an earlier deployment, this time in USS Forrestal, McCain was involved in a flight deck fire that erupted when a missile, loaded on an aircraft getting ready for launch, misfired, striking an external fuel tank on another aircraft, and leading to a rapidly expanding conflagration. There's a famous film showing McCain exiting his flame-engulfed A-4 aircraft by gingerly walking out on the aircraft refueling probe to a point just beyond the flames.
After his release from the Hanoi Hilton and his subsequent entry into Arizona politics, McCain spent ten days at sea with us on USS Dwight Eisenhower while I was XO. In several long conversations, he left me with the impression of a very smart and canny guy, still with a bit of a chip on his shoulder, but no false pretenses or posturing. I found him to be a good guy and very likeable, but also one who reminded me of the old joke about Irish Alzheimer's ... "they forget everything but the grudge."
I can think of no other pair of people less likely to be able to understand each other than Trump and McCain