Found it. (By accident, as it happens.)

Here's Obama referring specifically to Bush and McCain:

Obama began his day Wednesday in Springfield, Mo., charging: "Nobody really thinks that Bush or McCain have a real answer for the challenges we face, so what they're going to try to do is make you scared of me. You know, he's not patriotic enough. He's got a funny name. You know, he doesn't look like all those other presidents on those dollar bills, you know. He's risky."

No, Bush and McCain haven't. And there's no other "they" lurking in the sentence to be referenced.

Here's the original article.