Sam's latest post (and the comments) got me thinking about the structural relations of race in relation to those of gender and sex. Sex is a biological category, and gender is social. Those with more liberal attitudes about these things tend to include most sex or gender differences in the category of gender, seeing as much as they can as illegitimately forced perceptions of male and female not required by biology. Sam was arguing for a conclusion on the other end of the spectrum, that there isn't anywhere near as much to gender as opposed to biological sex as many people seem to want. I gave some reasons in the comments not to take it so far. People of all political persuasions will want to see some inappropriate gender standards that aren't dictated by biology, and most people don't seem to have a problem even with some socially-determined gender differences. It's not as if most people who affirm the distinction think everything about gender is wrong.
Anyway, that's all in the comments. You can read it there if you want more. What's interesting to me about this right now is its bearing on questions about race. We can separate gender and sex without having to do conceptual analysis to see what our concept of gender refers to in the world or what our concept of sex refers to in the world. These terms have been defined by those who study this issue. The debate is over which elements of our more general sex/gender concepts fit into each category. In race, the debate is at an earlier location. We can't even agree on what criteria are used to determine racial categories. This is because we're trying to do conceptual analysis. We postulate a single concept of race and then try to figure out what that concept refers to in reality (if anything). That in itself will explain some of the differences here.