If Biden drops out of the race now, he will have to resign the presidency as well

Well, it’s pointless to talk about the other guy, his insanity, though well-documented, is of no interest to the voters. They prefer to laugh at a man who has grown old in the service of his country, taking many personal losses along the way.

As for this:

I can only quote Burns (“translated” to plain English):

Oh, would some Power the giftie give us
To see ourselves as others see us!
It would from many a blunder free us,
And foolish notion

I blame his advisors, who hadn’t the courage to point it out to him in no uncertain terms, when it might have done some good.

Right. But Trump’s example is (I’d hope) not some sort of gold standard, such that if Biden is no worse he’s obviously beyond reproach.