How do you deal with racist people?

I live in Texas, and unfortunately, many people here are still very racist especially in the smaller towns. I hear racist jokes and comments at work, in public, and sometimes even receive emails or texts with racist comments. I don’t think they’re funny at all and feel that I have made that clear to people, but I’m still surrounded by it. When I hear a comment in person, I tend to just walk away or ignore it. When I receive an email or text, I just delete it. What I want to do is respond in a way that makes the person feel ridiculous for making such a comment in the first place, but I usually don’t feel like arguing with people like that, if you know what I mean.

What is the best thing to do in these situations? What do you do?