Not Bush, sadly. Allen. The Revealer suggests that he's done because, in order to run for Prez, he'd have to be the Xtian Right candidate. And they don't want the baggage.
To be honest, this doesn't shock me. After the whole "macaca" thing, when the noose in the office became more common knowledge, it seemed impossible to me that he had a prayer of running, let alone winning.
But then, I am an idealist.