HCR Countdown: Where's Biden?

A perspicacious reader writes:

What, of course, is interesting about the arm twisting of undecided congressmen is how little Joe Biden is involved. You would think a guy who was in Congress for forever would be able to convince colleagues, or at least would be tasked with such an assignment. That Obama is doing it personally reflects little confidence in Biden and also a micro-managing of the legislation he refused to be involved in drafting and ironing out. Compare with Bush, who delegated this responsibility to Cheney, who was apparently far more effective than either Biden or Obama. Certainly his victories were less public so there were not quite so many process stories, which seem like the only articles coming out of the White House any more.

One possibility: Obama doesn't want Biden anywhere near Congress because he fears our intrepid vice president, God love him, would make yet another silly gaffe.