If my grandfather did that, he wouldn't do it a second time (at least, he'd know he'd better not do it within my hearing). Not that either of my grandfathers would have done that (I think).

Yes, I know, grandfathers with thicker heads than mine exist. Even if they can't get it through their heads that such views are wrong, maybe they can understand that people get in their grill every time they say it, and the whole family turns against them. After a few times, they may start to get the idea that they shouldn't say such things. (Or maybe they never will. Either way, I don't think I'm going to let racist comments about individuals slide in my family.)