A thought experiment about creating and valuing lives
Roe v. Wade does not say what you may think it says. Yes, it creates a right to abortion that cannot be unduly interfered with by the states. But it explicitly states that there are two interests that must be balanced: the woman's privacy interest, and the state's interest in protecting the "potentiality of human life." If this "potentiality" for life could somehow be protected without unduly interfering with the woman's right to end her time as involuntary host organism, it would seem that this would be completely constitutional (not to mention wildly politically popular).
How would that work?
Step 1. Technology is developed such that an implanted embryo may be removed and transplanted to a different woman's uterus.
Step 2. Such technology becomes cheaply available.
Step 3. Lots of wombs in poverty-stricken slums are available for rent. (Check.)
Step 4. New Abortion: for the same price and the same intrusiveness of a standard termination, your uterus is scraped and the embryo harvested, shipped to Nairobi, and implanted in a starving woman's uterus, and after gestation, the child is raised until age 6, when he or she is sold to a factory or a brothel.
This procedure could give the precious gift of life to over a million babies a year from the United States alone.
To those who object on sentimental grounds, I direct them to Robin Hanson: do not slum children sold into prostitution also smile? Isn't the only relevant ethical question whether those children would themselves find their lives to be worthwhile?