To me a racist is anyone who has hate in their heart. For example, anyone who has a website that calls itself retard.com is full of hate. Do you think it's okay to hurt and demean people with special needs? That's what you do by calling your website retard.com
Do you think that people you haven't said anything hurtful directly to a person living with special needs that it's okay?
Well, it's not. You take away their dignity when you use the name in a casual statement or remark.
Maybe you don't have a member of your family living with special needs. If you ever do you'll know what I'm talking about.