In a truly moral society, the highest aim would be a protection of the innocent. And every adult would be expected to put aside his or her self-centered needs and to act in the best interests of those who cannot yet defend their own interests.
The moral question in the case of abortion is: Whose interests come first–the unborn or the already born?
Societies shift in their demographic makeup over time according to relative birth rates, among other factors. If abortion were prohibited, and thus irresponsible adults forced to bring pregnancies to term, not only might this relegate the infants to nightmarish parents and lousy role models, absent adoption; but such parents, by virtue of genetic combination, would be much more likely to have children who exhibit those same immoral tendencies. In effect, this would tilt the gene pool toward the irresponsible and the immoral.
Denying what are by definition unfit parents the right to prove their real lack of fitness by aborting their own children spares the lives of their unborn by sacrificing the future for everyone else’s children, born or not. Whether through welfare entitlements or outright imprisonment, these spared children, many predisposed toward immorality, will likely impose various costs upon their contemporaries.
Abortion is an abomination. And while the issue of moral guilt becomes less clear with regard to non-adults, as well as to rape victims and to medical emergencies–non-adults owing to their lack of a matured competence, the latter two to a lack of realistic alternatives–abortion ought nevertheless be discouraged by any means short of legal prohibition, threat, or actual violence.
No doubt many wonderful children and successful adults were born under adverse genetic circumstances. But we are self-evidently born, not as blank slates, but with inherited dispositions. And the future of a society, and of a democratic society in particular, is very much a numbers game. Thus the blanket prohibition of abortion, however well intended, greatly stacks the odds against the majority of living children.