The job of any politician, including the president, is that of a custodian. What we need is to elect eminently qualified custodians and not dangerous demagogues who wish to take us back to the dark ages.
For every advance we make, there are those who wish to take it away and those who just love to cheerlead them on because it hurts or harms others. That's a real, bonafide pathology and anyone of that disposition should be weeded out and banned from holding public office. But it's much too late for that.
As for Joe Biden, he's not good at public speaking but he still has all his marbles. Just ask any Republican who's discussed matters with him in private. They all say he's sharp as a tack and can't be fooled by the same tactics they use on their cult.
All the best,
Nonoise