Sorry for not replying here sooner. I saw this thread last night, after I’d had some friends over for dinner, and it didn’t seem like “half in the bag” was the best frame of mind in which to write a response.
Anyway. The subject is currently under discussion in the mod loop. While we haven’t reached a consensus yet, I thought I should, at least, explain why I didn’t moderate the comment when it was initially reported.
To start, I’m not really sold on the idea that the term is racist - at least, not the sort of racist that normally gets moderated around here. Certainly, it’s an artifact of a much more racist time, and makes reference to a theory of race that’s been thoroughly discredited, but the referent seems to be derived more from the idea, “People with this particular condition kind of look Asian,” and less, “People with this condition are stupid like Asian people.” Certainly, the former is very much not cool, but it feels (to my admittedly lily white ass) to be a different kind of animal from outright hate speech - more akin to “Oriental” or “Negro,” and less “chink” or “nigger.”
The argument that it’s insulting to people with Down Syndrome is much stronger, but also not something that we have a lot of precedent for moderating on the SDMB. I’ve always been hesitant about moderating ableist speech, because it seems like a genuine slippery slope to me. If we ban “mongoloid,” why do we allow “retard?” If we ban “retard,” why do we allow “moron?” And so forth. It’s a can of worms I’m not hugely anxious to open, because it seems the only way to resolve it is by creating arbitrary distinctions between effectively identical terms, and that’s a hard way to moderate a message board.