A Macaca is a Macaque, a North African monkey that follows you around, begs for food, tries to get its hand in your pocket, tries to steal shiny objects, and generally makes a nuisance of itself.
Really, it was a very good description of this rat operative who was following him around videotaping him and trying to get something on him. Apparently his staff started calling him the macaque, and he went and used it in public.
Now, the establishment is on him because the kid is indian-american, i.e., dark-complected. As usual, they forget that according to their Prophet Darwin we are ALL monkeys.
Right, we're all just monkeys that figured out how to get out of the trees.
That's one explanation. The one Allen gave initially makes much more sense. After all, this little punk has a Mohawk haircut in profile. He's ridiculing American Indians.