pardon power is absolute. I’ve heard some Lefty wags claim that Biden can’t pardon his son. But that is total nonsense. He can. OF COURSE he can. Whether he will or not is a totally different question.
And if he did so it would just wreck the Democrat party! But he certainly could. And I would be surprised if it doesn’t.
How it will probably happen is that the Democrat party tries to ditch Joe Biden and so in a fit of self-serving pique he pardons Hunter. It truly IS a break-the-glass move.