They’re the people who, when filling out a form asking for their ethnicity, cross out all the options and write in “American.” It’s been many years, but I did read several papers on this issue when I was working with semiotics. It’s a bigger phenomenon in the South (“American by birth, Southern by the grace of god”) and the Midwest.
And I didn’t mean to imply that they were all racists, just that there’s a known correlation that has been studied by sociologists. I also didn’t mean to imply that they’re the only racists. Hell, I’ve been to Boston…