Racialicious links to a post asking how racism harms white people. It's a good question that I think whites and non-whites should spend a lot of time thinking about, and I don't think most of the comments on that post have really gotten to the most fundamental issues. The question does assume that there is never any anti-white racism, which would be a mistake. A question that would better express the original intent is "How does white racism harm white people?"
I would think that the primary way racism of any sort harms the racist themself is that it is bad to be a racist. It's just bad to be bad. It's bad for you, not just because it has bad consequences but merely because it's bad to be bad. You harm yourself intrinsically by being a bad person.
But there are all sorts of bad consequences of racism on those who are exhibiting it. One is that much of what's excellent in the culture that surrounds us, including things racists appreciate and rely on, is due to those racism harms and victimizes. So there's a kind of inconsistency in any kind of racism that names things as bad in the person one isolates as "other" while recognizing any of those good effects as good. It's bad to be inconsistent, because it's irrational. So that's another negative impact of racism on racists themselves.
We need to distinguish between racists as evil people with evil intent and other kinds of racism, which don't all involve racists. Lots of people contribute to institutional or structural racism by taking part in practices that in effect harm people along racial lines, even if the people involved aren't racists. Also, virtually all white people are affected by residual racism, which affects our unconscious responses and attitudes to non-whites, all the while not constituting what it is to be a racist. Both of these have similar characteristics with being a racist, in that it's bad to take part in bad practices and to have bad unconscious responses to people, even if such things don't make someone a racist.
More generally, and perhaps most fundamentally, we're all morally and socially interconnected, and harm toward an entire community of people is thus harm toward an entire segment of humanity, and we're all part of humanity. Thus harm toward other human beings of any sort (including racism) is thus harm to ourselves inasmuch as we are all human. Crimes against humanity are crimes against ourselves. So even any racism that I have nothing to do with causing or perpetuating is a harm to me, even if I'm not the immediate victim. All racism is harmful to all human beings.
It's only after all that that I'd bring in things like how our lives will be better off externally when we interact in a moral way with those who are different. It seemed to me that most of the comments on the post that started this were focusing on those questions, and I thought it was worth taking some time to reflect on some deeper reasons.