I spoke with a woman today who was referring to a friend with the last name of "Houston." I wasn't sure I had caught it, so I asked "Houston? Like the city?"
"Yes," she said "but she doesn't have anything to do with Texas. She's not a racist."
People might think things but not say them out loud, unless they believe that all the important people agree with them. It takes a special arrogance to say some things out loud. Yet I suppose, if you can stereotype at that level, you are already beyond the point where reason will affect you.