I suppose I could. I was going for the "Tropic Thunder" line. But really, political correctness? Has anyone ever called an actually mentally handicapped person "retarded" in the past thirty years?
By the way, the euphemism treadmill of this subject has proceeded to the point where "mentally handicapped" and "mentally challenged" are also now politically-incorrect. The preferred term is now "intellectually disabled" or "learning disabled" (which to me is far more insulting than "mentally retarded", from a literal perspective, but less evasive than "developmentally delayed").