The other day, Twitter commentator Tom Joseph (@TomJChicago) remarked Trump was demented and that this was being covered up by his medical examiners. @duty2warn, a group of psychological professionals, has make similar remarks but instead adds that Trump will never submit to a proper examination. Let us, for the purpose of argument grant the possibility that Trump is demented.
If so, then various Trump officials, as well as foreign heads of state, are taking advantage of this. It seems likely enough; Trump’s pronouncements on Putin and Kim Jong-Un do not seem the thoughts of a sensible person, and there is precedent for this in Ronald Reagan, who had memory lapses and public bouts of confusion. It is hard to be sure; dementia hides itself. In early stages the victim has good days and bad and remains competent at activities they are already skilled at, even though they will be bewildered and lost when they leave their area of competence.
If this is so, part of the reason Trump relies on family, and especially his daughter Ivanka, is likely that they have been covering for him for years, and so Ivanka putting herself forward at inappropriate times (most recently at the 2019 G-20 meeting) is a matter of her trying to cover for her father, similar to the way Nancy Reagan covered for her husband Ronald.
Now I turn to history. King George III was said to be mad, with fits of mania, as early as the 1770s. Diagnosing a historical figure is difficult at best; physicians of King George’s period did not have a modern concept of illness, so that their diagnoses do not translate well into modern terms, and not only does mental illness often hide itself, but King George’s courtiers, friends, and family had excellent reasons to conceal his difficulties. Again, let us grant the likelihood. It is fairly high, with a modern study of his letters showing symptoms.
It seems likely, then, that the king’s mental illness contributed to the grievances of the founders of the United States. It is all rather mythic. The mental illness of a ruler contributed to the foundation of the United States and now the mental illness of a ruler may end the United States.