YEP, HE SAID IT
Or at least Fox News quoted him as saying it:
BUSH: ...You know, I've always tried to lower expectations, and I feel like if people say, well, you know, maybe, you know, I don't think you handle the tough job, and when you do, it impresses people even more.
CAVUTO: Yes. He [John Kerry] was billed as the intellectual, though, and you had better grades in college.
BUSH: Yes. Well, as I said, I like to lower expectations.