"We need not resolve the difficult question of when life begins," said Justice Harry Blackmun in Roe v. Wade.
This decree minimized the fetus to "potential life." This assumption was needed not because of non-consensus of the beginning of life but rather because a fetus cannot be the moral equivalent of a baby when killed. In fact, the court directly asked, "Why would the State be compelled to protect potential life?" But what about scientific evidence? Biology does prove that life exists at conception. A human zygote, embryo, and fetus are just like a baby with a separate, real, living existence. By looking at real evidence, deductive reasoning could have presented questions such as, how can "potential life" be living? Or if a fetus is not human, why does it have to be killed to have a successful abortion? Then more questions like: How human does one have to be to be human? Or what if late-term abortion looks like infanticide? The ensuing discussion would reveal that the framers and those that ratified the 14th Amendment had previously written statutes in 30 of the 37 states to replace common law on criminal abortion. The court could've seen how they understood in high regard the personhood of human fetuses and the value of their lives. This would've been a presumption, but more reliable than the assumption that common law on criminal abortion never recognized the fetus as a person. They could then discuss the English jurist William Blackstone, who collaborated on such common law in the 18th century; he defined a person as, "One like us who had been formed by God in the womb."
Obviously, revisiting Roe won't be at the same time, but the unborn child will be in the same place — alive and kicking.