Gee, why isn't this considered a 'racial' slur?

Chris Rock's "Zebra" president and "ignore his whiteness"

"Thursday morning, comedian Chris Rock said that his recurring zebra character in the animated Madagascar series of movies is 'in honor of our zebra President [Barack Obama].'"

"NBC’s Today Show host Ann Curry asked Rock the important question regarding his role as Marty the zebra: 'If you could be any animal in the animal kingdom, Chris, what would it be?'

“'I wanted to be the lion, you know, king of the jungle and all that,' he replied, 'but that didn’t work out. Snake is always good. You know, scare people. But I’ll take the zebra.'

“'In honor of our zebra President. Black and white, white and black. … I love our President, but he’s black and white. He appeals to all. And that’s what I am going for,' the comedian said.

"Curry wondered aloud how the President might react to such an analogy. Rock laughed and replied, 'I don’t know. … We ignore the President’s whiteness, but it’s there. It’s there.'”

Gee, not that such comments would be racial slurs or anything. I guess in these times so corrupted with political-correctness, everything just depends on who is saying it. I can imagine the uproar if a white person - particularly a Republican or Conservative, comedian or not - were to say such stupid things.