Currently, abortion is generally legal in the United States through all nine months of pregnancy (except in about 11 states) for generally any reason. Our government recently decided to vote on whether or not to ban sex-selection abortions, but ultimately decided not to ban them.
At first blush, this seems pretty ridiculous to me. However, upon closer examination of the pro-choice position, can you really blame them? When the Roe v. Wade decision was passed, the Supreme Court decided that no one can tell when human life begins (despite blatant scientific evidence to the contrary), then took it upon themselves to declare that life begins at birth and made abortions legal through all nine months of pregnancy.
Now, if the unborn are mere "clumps of cells" or "tissue," and are not "humans" as we are, then why is sex-selection abortion wrong? If a couple is trying to conceive, is the father wrong for hoping he gets a son? As long as he doesn't mistreat or abuse his child if she turns out to be a girl, of course it's not wrong. In fact, if the unborn are not part of the moral community then, as SPL member LN once argued, having a sex-selection abortion is the moral equivalent of a man getting a vasectomy because he may produce female children in the future.
Polling data actually suggests that the majority of Americans (in fact, 86%) believe that sex-selection abortions are not only immoral, but should be illegal. So let's take this a step further by using a technique that Scott Klusendorf and Greg Koukl have dubbed Trot Out the Toddler. Say a woman gives birth to a girl and when the girl is two, the father decides he doesn't want her and wants to try again (he really wants a boy). Would he be morally justified in taking the child's life because she's female? Of course not! So why do we feel so strongly that sex-selection abortions are horrible? Could it be because the unborn that we are aborting is a human? Why would sex-selection abortions be a human rights violation based on gender, if abortion itself isn't a human rights violation based on their humanity?
Steve Wagner, in his book Common Ground Without Compromise (p. 53), suggests disgust over sex-selection abortions might be for one of at least three reasons: It's sexist, it's a crime against society, or it's a crime against humanity. But none of these reasons work unless the unborn are actually human. If it were merely sexist, then this could be remedied by ensuring that an equal number of male and female fetuses are aborted. Yet no one recommends killing male fetuses to balance the numbers out. It's not a crime against society. Concerns for the beauty and order of society do not really account for our disgust. It is perceived as wrongs not against something but someone. And it can't be a crime against humanity unless the beings being wronged are actual humans. Potential humans cannot be harmed. In order to be a potential something, it is an actual something else. If it is merely a potential human, that would make it actually something less significant, like an animal mass or tissue organism. But it is not a crime against humanity to remove a piece of tissue or kill an animal organism.
The pro-choice position is that all women should be able to abort because abortion is inextricably tied up into a woman's reproductive rights. If you believe Thomson, that a woman should be able to abort because she should not be legally compelled to give her body as "life support" to the child, then you must also agree with Thomson that she can abort for any reason, even if you, personally, find the reason unpalatable. And if your position is that abortion is permissible because the unborn are ot part of the moral community (that is, they are not yet a "person"), then you're not really causing any harm to anything by having a sex-selection abortion.
This is why Christopher Kaczor argues, in his book The Ethics of Abortion (p.198), "Discriminating between non-persons, for example plucking the red roses but leaving the white, is not ethically problematic in itself, since these plants do not have rights nor do they merit equal respect as persons." Sex-selection abortions are simply not morally problematic unless the entities being discriminated against are fully human with the same moral worth we have.