This is a response to the way that race is used as an analogy to argue that transwomen are not women because, just as one cannot change one's race, one cannot change one's sex. (And let me apologize in advance, should I say anything someone else has said first that I didn't know about.)
First of all, the vast majority of humans are born members of a sex. We are then assigned a gender on the basis of our genitals, and the gender roles that follow are socially constructed (we know this because they differ historically and culturally). But we are born into bodies that are sexed.
We are not born with a race. The race that we are assigned is socially constructed (we know this because racial categorizations differ historically and culturally). Our bodies do not hold essential racial truths. For example, people who are considered to be Black can have light skin, European features, straight hair, or blue eyes - or all of these at the same time. There are no essential racial charateristics that hold true for all Black people, or for all people of any racial group.
Further - in the early part of the 1800s, the Irish came to America and found that there was a racial caste system. Guess where they fit in? They were not white. They were called the Black Irish, Smoked Irish, N------ turned inside out. They were not thought of as property (as were enslaved Blacks), and so they were thought of by white Americans as lower on the racial status ladder than enslaved Blacks. The Irish were the ones who were brought in when you had really dangerous and unpleasant work to do, because if an Irish worker died, well, at least he wasn't anyone's property. Italians and Hungarians, as well, were not considered white when they first got here. That all of these groups (and more) are considered white today just proves that notions of race are social, not essential.
Moreover, there are anti-whiteness activists who argue that, indeed, it is not only possible for whites to reject their whiteness, it is obligatory. They see whiteness, not as a simple social category, but as a category that affords privilege and power at the disadvantage of those who do not get these same benefits. They see whiteness and the belief in whiteness as buttressing the entire racist project - and they suggest that one way to undermine systematic racism is for whites to refuse to be perceived as white (by, for example, telling people that they are Black).
How well this works in individual situations depends on those situations - but at the very least, it does make people who think they're white, THINK.
So what does this have to do with sex and gender, you ask? Well, as race is not immutable, it is not a good analogy to make when one is trying to justify reserving sexual identity for those born with certain body parts. There are and have been societies in which one's genitals do not determine one's gender - one's role in the community does. In this society, as well, sex does not always determine gender. For example, in the queer community, there are any number of genders, regardless of sex. Butch and femme are just two genders, available to both men and women.
But let's say that we apply the definition of "woman" to only those people who are born with certain female body parts. What happens to the term if transwomen, then, are allowed to claim it?
Well, what does happen? When I was in college and transphobic, I felt really upset at the idea that (as I saw it then) some man could be part of my community, that he could claim my gender identity and experiences. And this was upsetting to me, in no small part because I was just claiming my feminist and my women's space.
I don't remember what it was that turned me around. Possibly it was that I met some transgendered people and it was no longer a theoretical issue any longer. Interestingly enough, only *one* of the transgendered folks I know has ever acted in ways that ever brought out the "man taking over women's space" demon that I thought I had exorcised. (And that was still just bigotry on my part, as I've known lots of women who've been just as insistent about their issues as this one transwoman has been.) Meanwhile, of the lesbian separatists and the radical feminists I've known? Lots and lots have shouted down other women, silenced men and women and lesbians and bisexuals. And you know what that tells me? That behavior isn't gender-based or genital-based. A person can be an asshat regardless of whether s/he pees standing up or sitting down.
My assessment: the anti-trans stuff I've been reading in the feminist blogosphere is born of fear and anger. Both exist for very rational reasons. Being a woman, being subjected to all kinds of assault on a regular basis, justify fear and anger. But - not toward all members of a group indiscriminately.
There also two other fears involved here. The first is that, if we open the door and let everyone into our movement, we will not be safe. We do not believe that we are capable of working in coalition without risking ourselves. Indeed, there is always risk in coaltion, but refusing to move forward and stagnating (by which I mean reproducing the same feminist theory that's been coming out of certain portions of the feminist movement for the last thirty-five years) is not a good place to be.
The second fear is that, if we let everyone in, then we will have to change ourselves, and that might mean setting aside some of our feminist theory so that we can work with people who are significantly different from us. We might have to work with people we hate! And what kind of movement would that be?! Anti-porn activists working with prostitutes to fight domestic violence? Transmen working with radical feminists on Take Back the Night? Lesbians and Trade Unionists fighting for decent pay? Well, why the hell not?
And finally, there is this: if *anyone* can call themselves a woman, then what does that mean for the integrity of the definition that applies to biological women? Or, alternately, if a woman who sleeps with men can call herself a lesbian, then what does a woman who is completely devoted to women and would never think of sleeping with a man call herself? ...Or...if same-sex couples get married, then what does that do to the meaning of marriage for heterosexuals?
(I'm actually more sympathetic to the desire to claim identity labels and to keep the definitions somewhat "pure" than I sound here - but it's hard to avoid taking this argument to its natural conclusions.)
At any rate, it's 2007. It's time to stop reinventing the wheel and start getting on with the job.
~climbing down from soapbox~