It's clear now that Mitt Romney was being funny when he made his crack about rolling down an airplane's windows to let some fresh air in. But in response to that episode, plus my mention that Romney is said to be an uneasy flyer, a reader highlights what I consider the most underappreciated reality of political life. That is simply how exhausting it is, and how important sheer physical stamina turns out to be in having a successful political career.

I was in my mid-20s when I worked and traveled in Jimmy Carter's campaign, and I remember joking bitterly that I felt like I was getting a year older, in a bad way, with every passing day. That was because of the endless sequence of midnight hotel check-ins, wee-hours meetings and deadlines, 5:15am musters for the next stop, and bad food and motorcade bus rides in between. This note, from a reader who is a professor at one of the U.S. military's war colleges, goes on to explain the point:



Part of the job of President is to spend a LOT of time on aircraft, both airplanes and helicopters. There's no way to avoid doing so, and the rigors of the job mean that you need to able to use the time productively for sleep and getting work done. You often talk to the press while onboard or immediately after landing. And you need to look, well, "Presidential" the moment you walk off an aircraft, often to immediately engage in a highly visible public event.



Clearly flying is not such big issue that it significantly impairs Romney, but if flying knocks you down even a little, or just gives you an unhappy day, that's not a small thing for a U.S. President.



This highlights how important the basic physiological demands of the job are. I'm a small cog in the national security machine, and as a middle-aged cog I've come to peace with it being very unlikely I'll move up from cog to prime mover. I just couldn't handle it physically.



I need 6 hours of sleep or I get ill pretty quickly; my sleep is easily interrupted by noise, motion, or stress; several weeks a year I'm sneezing, dripping, and hoarse from allergies; my immune system and my gut are only average at fighting off challenges; etc. In short I'm pretty normal, but a "normal" person can't be on -- looking, sounding, thinking, feeling great -- almost every day, busy 16 hours a day, travelling frequently, meeting vast numbers of strangers, not necessarily having much control over meals and bathroom breaks, all while making stressful decisions, without just falling apart.



About the best argument I see for the crazy long campaigns we have is to see if the candidate's body is up to the job.



I hadn't thought about it that way, but having been prompted to think about it, I agree. To be clear: this is not a partisan but a human observation. It is amazing that the four people left on the national stage -- Romney, Obama, Ryan, Biden -- bear up as well as they do. Normal people could not stand the strain.