Biden is an idiot; but he's also the Vice President of the United States.
He can't be a total fool to have gotten there. The good thing is that Ryan is bright enough to know the same thing. No way will Ryan underestimate his opponent.
If I were Ryan, I would recall the look on Cheney’s face at the inauguration and be on guard.
I would be as cautious in the debate hall as if in a rattlesnake den. Caution means keeping a careful eye and ear and gun and hand grenades at the ready.
I actually think he can be a total fool. I think Biden was bought and paid for and his owners didn’t want someone too bright who might connect the dots or ask questions. They wanted an amiable doofus who would do as he was told.