Obama cannot publicly accept any restriction on abortion, because to do so would alienate several of his core constituencies. Feminists and Planned Parenthood see abortion as a sacrament and a cash cow, respectively, while greens see population control as a necessity to prevent environmental damage (they buy off on the Malthusian idea that people are simply "useless eaters", rather than, well, people). Socialists and communists see abortion as a means to undermine family cohesion (pregnancy is a forcing function to marriage) and a promiscuous, hedonistic state is more receptive to their message than a stable, family-oriented one.
However, his refusal to even contemplate restricting abortion for something as petty as sex selection (which almost always favors boys over girls) renders him vulnerable to a number of political arguments. First, the whole war on women thing becomes harder to promote with a straight face when you favor aborting female babies for the crime of being female. Even the Taliban isn't that misogynistic. Second, the use of abortion for sex selection raises the specter of China's one-child policy, and their program of forced abortions and infanticide. At what point would Obama object to the killing of a baby for being female? First trimester? Second? Third? The Chinese have forced women to abort at every stage of pregnancy, and even killed babies shortly after. Here's one description from Stephen Mosher, who documented Chinese abortion practices during his doctoral candidacy at Stanford:
Mr. Mosher subsequently published his findings in the widely-acclaimed book Broken Earth: The Rural Chinese, and now serves a president of the Population Research Institute. He describes his turn from being a vaguely pro-choice academic to pro-life activist, beginning with his witnessing the women undergoing forced abortions:
“They were crying, begging for mercy and praying for their dying children. It’s one thing to think about abortion in the abstract, but when you see a baby at seven-months gestation, it’s a baby — truly one of us.”This is ugly stuff, but it's stuff that the abortionists cannot allow to see the light of day, because ultimately, this is where their policies lead us. So, okay, Barry, when is it not okay to abort a baby?
In hindsight, he says that visit to the Chinese abortion facility forced him to abandon his casual, untested adherence to moral relativism and embark on an uncharted spiritual pilgrimage.
“On a scale of evil from 1 to 10, this was a 10. And if there is absolute evil, I concluded that there also must be a counterbalancing absolute good — or the universe would be truly mad.”