How do I raise my kids not to be racist?

I live in a very white state. Whenever my family is together and gets a little tipsy, some of them say horrific things at random intervals in front of my children. I have expressed to my siblings many times that we have different views on stuff and they should knock it off in front of my children, but their husbands get drunk and try to screw with my cool on occasion.

Is this just a discussion with my children after? I am seriously wondering how to approach this with my children. Do I tell them some adults are stupid or what?