Why do you have Nipsy Russel pretending to be President?
Actually, the only amusing Obama-cature I've seen so far is what Tom Toles does in the Washington Post. And that's just a few squiggles. It won't work in 3D.
I don't think anyone has nailed it yet. He's a bit like Gerald Ford in that he presents no remarkable features for exaggeration. He's black and that is novel for a President but the cartoonists who try to derive their satire from that seem to be the most unfunny. It's not the defining attribute. It's not that essence that makes for caricature.
Richard Nixon had a unique nose and jowls that became iconic, but Obama being black... well, him and 40 million other people in this country.
I saw some video of the new Obama robot in Disney's Hall of Presidents. It look nothing like him. It's like they decided "Will Smith is close enough, right?"