Old Folks Home
Warren, the youngest, is 70, so they are all in their eighth decade. Of course she is also the smartest, so that should count for something.
Ronald Reagan, the only President of comparable age before Trump, and whose Alzheimer's became severe during his second term, was younger than any of them when first elected.
The others on the debate stage next go-around, AKA the Seven Dwarfs, don't look especially promising either, but maybe one of them can make a move.