At the same time, the resurgence of the slur “retarded" serves as a blunt bookend to the obsession with genius. The term was once a medical diagnosis gleaned from intelligence scales before it transformed into a pejorative and finally became largely unacceptable in the aughts. But it can now be heard again in the speech of certain venture capitalists, political operatives, podcasters and comedians alike. In its current use, the slur mocks disabled people, marks political opponents as inherently inferior, and signals the rise of a new elite to whom the old rules of civility do not apply.

(http://www.autoadmit.com/thread.php?thread_id=5705980&forum_id=2:#48819576)