Atrios comments on George Bush's use of language:
While I don't think Bush referring to Obama as "this cat" is really racist, in the sense of suggesting some sort of animosity towards people of color, but I think there's a reasonable chance that race played a part, in the sense that Bush would've been much less likely to refer to a white guy with that term.
But from the same article, here was Bush on another occasion:
The president asked his secretary, Karen, to bring him the Rose Garden remarks he’d just delivered that day....When he finally got them, he put his half-glasses on and looked at them. “See, this was fine today,” he said. “But we got to make this understandable for the average cat.” He proposed an outline for another speech that talked about the situation our economy was in, how we’d gotten here, and how the administration’s plan was a solution.
I think Bush just has an odd attachment to calling people "cats." Surely some other former White House staffers could enlighten us about this, though.