I remember when Reagan was found to be losing his grip of reality a little, they whipped him off the hot seat as soon as the very first signs of infirmity started to appear. I remember how shocked everyone seemed to be, to realise they almost had a demented person in control of the whole of the US, including all the nuclear weapons, which were still pretty much loaded and aimed at the time.
The horror is what I remember.
Now we seem to be sleepwalking into the same scenario, and no-one bats an eyelid.
Further, dementia was something pretty unusual at that time. Now we seem to see it everywhere. We always had old folks, but most of them seemed to get through most of life without losing the ability to think for themselves. Something is making us insane I think.