Up until Trump, GW Bush was the dumbest president ever. Like Trump, he had a hard time focusing on his morning intelligence briefing, so they started making the first page a Bible verse. That way he looked forward to opening the file.
Eh? Reagan was an actor, and not a curious mind. And Reagan had literal Alzheimer’s, as widely reported. Surely Reagan was the dumbest?

Alzheimer’s is NOT the same as being stupid, so while he WAS stupid, that’s not why.

It’s pointless to have an argument about which was the stupider president before Trump. I think it was GWB, you think it was Reagan, and there is no source that will decide it.

Alzheimer’s is NOT the same as being stupid

That is just word games with the dictionary definition of “stupid”. Having Alzheimer’s surely makes you hugely unqualified to make good decisions as President.

Of course it does, but Alzheimer’s is a tragedy. I’ve watched very intelligent people close to me succumb to it, and I am particularly sensitive about it. They weren’t stupid, just old, and it caught up with them. We shouldn’t let that define their lives, even if we don’t like them.

Alzheimer’s aside, Reagan wasn’t stupid, he was just a typical narcissistic, Sociopathic Conservative, who just didn’t care about regular people. He wasn’t stupid so much as just plain mean. AIDS emerged during his presidency, and he made the conscious decision to ignore it, and just let it spread among the gay community. That’s Evil, not stupid.

GW Bush was a typical frat boy nepo-baby, had everything handed to him, and squandered it anyway, then failed upwards all the way into the presidency, primarily due an open cheating scandal managed by his much smarter brother, who probably would have been the best presidential candidate in the family, before HW and GW burned the family political reputation for all time, destroying any chance he might have had.

That’s my take on it, and you are welcome to your own.