The behaviors in those examples and longer, more contextual versions of it, sadly, aren’t entirely Biden’s fault.
For one thing, much is being made (not necessarily in those two threads) of Biden sticking his finger in the questioner’s face. I disagree: he was pointing, as many of us do, for emphasis and pointing in the direction of the man’s chest without pointing anywhere, or at anything, in particular. It wasn’t until the end that, in his zeal, Biden’s finger came up toward the man’s face.
More importantly, though, as is also being pointed out, that behavior and others like it in the last few weeks, strike me as consistent with, although not by themselves diagnostic of, early stage dementia.
This may be why Biden is being limited (I don’t see him limiting himself) to seven minute speeches (we’ve already seen him tire and visibly fade during 90+ minute debates), few interviews, few interactions of this type, few public appearances at all.
The foolishness and humiliation, though, are the fault of his handlers for continually exposing him and on the part of the Progressive-Democratic Party for letting this charade go on; although at this stage, Party really is limited on what they can do about it.
The best thing that could happen to him now—and best for Party—would be to encourage Sanders to destroy him at the next debate. Party can’t stop the fight on a TKO, but Sanders can go ahead and knock him out. Of course, a lot of that will be up to the debate moderators and how much they try to protect him. Biden is wholly incapable of defending himself at this point.
On the other hand, I’m not sure Sanders has it in him to deliver a coup de grâce.