Is it coincidental that both Reagan and Thatcher had dementia?

[BlueStreak]

18. It was the elephant in the room.

It became absolutely obvious by his second term. He muddled through the reelection somehow. He beat Mondale about 60/40 so he was never really forced out of his protective cocoon. But by 1986, he was a veggie. He couldn't complete a sentence on his own. I don't recall a single public appearance where he didn't have Nancy on his elbow finishing all his sentences.

But our wonderful press just ignored the fact that the most powerful man in the world had no functioning brain.

Mondale was surely aware of this and must have decided that he was going to lose either way, so it was best to just keep his mouth shut.

But my question really gets to public policy. The Reagan years (and the Thatcher years) resulted in radical right wing policies. I am wondering what role their mental deterioration played in that -- the idea being that in the early stages of the disease, they would have been less able to reason through the consequences of their policies. In Reagan's case, it sounds like he was pretty far gone, even as he took office in 1981. It is probably fair to say that for most of his years, he wasn't actually the President. These policies were pushed by others who propped his up to sell them.

The question is probably more pertinent of Lady Thatcher, who didn't show such obvious signs of dementia while in office.