[sparky_z]

I honestly don't think a person like you're describing actually exists (as an otherwise perfectly polite and well-adjusted member of society--including to members of that ethnic group that they interact with personally). But lets suppose for the sake of argument that they did.

I probably wouldn't invite them over to my house, nor champion their job application at my workplace. That goes beyond tolerance. But what I wouldn't do is try to get dropped from giving a convention talk (which they're qualified for), or seek to get them fired from their job or shunned from their peer group.