Language changes.
If you still say things like "I was gypped" or "I got Jewed on that deal" then knock yourself out, keep using the word retard.
> How are we to prevent retarded people from reaching positions of power
I work with people who have various learning disabilities who are in positions of power. Not just token power -- controlling hundreds of thousands of £s of power; part of recruitment and selection power; elected representative power.
Those people with a learning disability suffer real harm when you misuse the word retard to insult people without a learning disability. Not using the word isn't about protecting their feelings although that is a nice side-effect. It's about changing a culture where people with a learning difficulty are not murdered by police or allowed to die by doctors or discriminated unfairly against at work.
But all those other people that you call retarded? The ones without a learning disability? There are a whole slew of other, better, words that you could use. Your vocabulary is too limited and so your invective suffers.