I think people forget that Ronald Reagan was suffering symptoms of dementia during his presidency also...but they had the common sense to keep him off of TV. I'm sure there were people on the left pointing that out at the time, but I don't remember...I was 4. Biden is certainly not all there, all the time...for f*** sake, he can't even string 3 letters together in the correct order...and it's on a teleprompter screen right in front of him.
Now, Reagan wasn't under 24/365 scrutiny like today's Presidents/politicians are. I am a firm believer that there should be a maximum age for a President, just like there is a minimum age requirement. 78 is just too old to be in charge of a country.
If Biden wasn't a prominent political figure, they would have taken away his car keys a few years ago. He's 6 months away from mistaking the gas pedal for the brake and plowing through a farmers market.