Justice O'Connor, concurring.
The issue of abortion is one of the most contentious and controversial in contemporary American society. It presents extraordinarily difficult questions that, as the Court recognizes, involve "virtually irreconcilable points of view." Ante, at 921. The specific question we face today is whether Nebraska's attempt to proscribe a particular method of abortion, commonly known as "partial-birth abortion," is constitutional. For the reasons stated in the Court's opinion, I agree that Nebraska's statute cannot be reconciled with our decision in Planned Parenthood of Southeastern Pa. v. Casey, 505 U.S. 833 (1992), and is therefore unconstitutional. I write separately to emphasize the following points.
First, the Nebraska statute is inconsistent with Casey because it lacks an exception for those instances when the banned procedure is necessary to preserve the health of the mother. See id., at 879 (plurality opinion). Importantly, Nebraska's own statutory scheme underscores this constitutional infirmity. As we held in Casey, prior to viability "the woman has a right to choose to terminate her pregnancy." Id., at 870. After the fetus has become viable, States may substantially regulate and even proscribe abortion, but any such regulation or proscription must contain an exception for instances "'where it is necessary, in appropriate medical judgment, for the preservation of the life or health of the mother.'" Id., at 879 (quoting Roe v. Wade, 410 U.S. 113, 165 (1973)). Nebraska has recognized this constitutional limitation in its separate statute generally proscribing postviability abortions. See Neb. Rev. Stat. Ann. §28—329 (Supp. 1999). That statute provides that "[n]o abortion shall be performed after the time at which, in the sound medical judgment of the attending physician, the unborn child clearly appears to have reached viability, except when necessary to preserve the life or health of the mother." Ibid. (emphasis added). Because even a postviability proscription of abortion would be invalid absent a health exception, Nebraska's ban on previability partial-birth abortions, under the circumstances presented here, must include a health exception as well, since the State's interest in regulating abortions before viability is "considerably weaker" than after viability. Ante, at 930. The statute at issue here, however, only excepts those procedures "necessary to save the life of the mother whose life is endangered by a physical disorder, physical illness, or physical injury." Neb. Rev. Stat. Ann. §28—328(1) (Supp. 1999). This lack of a health exception necessarily renders the statute unconstitutional.
Contrary to the assertions of Justice Kennedy and Justice Thomas, the need for a health exception does not arise from "the individual views of Dr. Carhart and his supporters." Post, at 969 (Kennedy, J., dissenting); see also post, at 1012-1013 (Thomas, J., dissenting). Rather, as the majority explains, where, as here, "a significant body of medical opinion believes a procedure may bring with it greater safety for some patients and explains the medical reasons supporting that view," ante, at 937, then Nebraska cannot say that the procedure will not, in some circumstances, be "necessary to preserve the life or health of the mother." Accordingly, our precedent requires that the statute include a health exception.