I would no more make fun of a mentally challenged person than I would make fun of a sick person. That is not what retarded means to me. They are not retarded. The people in Washington are very.
I've wondered about this. People with developmental disabilities and/or intellectual impairment aren't professionally referred to as "mentally retarded" anymore, (nor are they called 'challenged', for the record). I'm not sure why using 'retarded' as an insult has gotten so much attention and reaction. I suspect that will die down in another decade or two. Perhaps people will have started using the term 'autistic' as an insult, and that will be the newest socially unacceptable buzzword?
Interesting that historically there have been a variety of terms used to classify exactly how 'retarded' people with intellectual and developmentally disabled were. Cretin, moron, simpleton, idiot, imbecile, feeble, and the list goes on.
Those who are doing the best work in the field understand that while it's always important not to inflict harm with name-calling and insults, what truly matters is doing everything possible to eliminate stigma and positively change how devalued people are perceived by society. This is what will make the biggest impact on the quality of their lives.