There is a broad topic to research. One thing it seems to me is the pre-dementia emotional states and attitudes lead to a lot of angry denial and fearful conservatism. The only ones left to go out and do crazy things, look and speak weirdly and team cheer plutocratic snake oil salesmen are vulnerable minds like these. Add that to anyone's natural denial and fear of inconvenient truths, especially personal responsibility and, voila, the Fetterman mudslide to grotesque irrationality. All of that is frustratingly exploited by the GOP and its Owners. Too easy. Too lazy. Too fatally unchecked. RFK jr is the icon of GOP voting base health outcomes. Abuse the body, celebrate with a diseased mind the Hell you voted for.
They will end up not having minds capable of reasoning at all. Not caring because the capacity is gone, maybe silly mellow enough instead of blank slate grouchiness to be less a burden on nursing home staff. If all the silent killers don't erase them first.
Aside from prying loose the political exploitation of the weak brained, humanity will have its best chance of survival by restraining and changing that Book of Revelation's one third, that irrepressible fun group in the Coliseum stands and elite money temples which drags everyone into colorful apocalyptic catastrophes every single time.