Trump and Biden have similar speaking styles and on top of that Biden has a stutter. The both ramble on incessantly. Trump probably has it worse than Biden because his arteries are clogged with hamburgers by now. Sure they are both slowing down, we all will when we get to that age but is it full blown dementia? If you want to see what that looks like watch some of Reagan's last public speeches, that will show you how dementia and a president look like. I have no doubt that Biden and Trump will not be running for election in 2024 because both really will be too old, but can Biden guide a team of people and make good decisions? Yes, no problem.