1. Word used to describe someone who is stupid and NOT someone who suffers from a mental disability. You can use it to describe a person who has a fully formed brain, but keeps fucking up.
2. Only an ignorant jackass would call someone who is mentally handicapped a retard.
3. Only a retard (see above) would be upset simply by the use of the word retard.
Sarah Palin is a retard; her son Trig is not.