Just read an interesting article on "defense of marriage" laws, originally written four years but recently updated. Here's the gist:
The biggest problem is that laws like the California initiative will make the courts decide who is male and who is female — and all available decision criteria create unavoidable miscarriages of justice that will, or should, dismay initiative proponents.That is, it's impossible, says Rick Moen, the author of the article, to give a biological definition of "man" or "woman", and therefore, impossible to define marriage as between a man and a woman. It's a cute idea, and I get why it would come from a site called LinuxMafia because it no doubt appeals to engineers who like precise definitions, but doesn't really work for a variety of reasons.
First of all, legal definitions are not the same as biological ones. I don't see why it's necessarily the case that, as Moen asserts, someone who has been a woman all her life, but is at some point tested and found to have XY chromosomes, must immediately have her marriage annulled and be permitted to marry a woman. The law is not, in fact, biology, and it has some give in it. It seems eminently reasonable that in a case like this, this person would (or could) still be legally considered a man. That may sound absurd, but it certainly doesn't to transsexuals, who may have some external anatomy changed but retain the same chromosomes.
Second, and even more problematic for Moen's argument, if this sort of test were that problematic, we'd already be drowning in "kudzu" (the article's basic metaphor is that marriage laws have unintended side effects like the introduction of kudzu to the American South has had). There are already all sorts of laws, regulations, rulings, etc. that differentiate between sexes and races. Questionable sexual identity is pretty rare. Questionable racial identity is extremely common, because it's almost impossible to test. And yet we have federal regulations mandating, e.g., that a certain percentage of contracts be awarded to businesses run by minorities. How can this possibly work, given that there is no feasible test that could be given that would verify the minority status of a given person?
So while marriage laws may and do have other pros and cons, we don't really need to worry ourselves about Moen's points. There's no kudzu about to overwhelm our legal system.