It's true. He really isn't. He's a white guy. That's why comparing him to a chimpanzee is not the same as comparing First Lady Michelle Obama to a chimpanzee. As lame and uncreative as the chimp/Bush references were and are (and, really, if you are someone who ever thought those were in the least bit funny or clever, you should really reconsider), there was nothing racially tinged about them. There couldn't have been: he's a white guy.
But this...this is as racially tinged--to put it mildly--as you can get. It's not even a close call: it is a direct slur against a prominent black person's appearance by comparing it with that of a monkey (well, a chimpanzee, technially, but not many peopel know that there's a difference). You think the term "porch monkey" just came out of thin air?
The Bush/chimp comparisons were not offenseve--they were just ignorant. This, though...this one hits far, far below the belt.