"Although Roe and Casey mandated a health exception for cases in which abortion is “necessary” for a woman’s health, the majority concludes that a procedure is “necessary” if it has any comparative health benefits. Ante, at 18. In other words, according to the majority, so long as a doctor can point to support in the profession for his (or the woman’s) preferred procedure, it is “necessary” and the physician is entitled to perform it. Id. See also ante, at 2 (Ginsburg, J., concurring) (arguing that a State cannot constitutionally “sto[p] a woman from choosing the procedure her doctor ‘reasonably believes’ ” is in her best interest). But such a health exception requirement eviscerates Casey’s undue burden standard and imposes unfettered abortion-on-demand. The exception entirely swallows the rule. In effect, no regulation of abortion procedures is permitted because there will always be some support for a procedure and there will always be some doctors who conclude that the procedure is preferable. If Nebraska reenacts its partial birth abortion ban with a health exception, the State will not be able to prevent physicians like Dr. Carhart from using partial birth abortion as a routine abortion procedure. This Court has now expressed its own conclusion that there is “highly plausible” support for the view that partial birth abortion is safer, which, in the majority’s view, means that the procedure is therefore “necessary.” Ante, at 18. Any doctor who wishes to perform such a procedure under the new statute will be able to do so with impunity. Therefore, Justice O’Connor’s assurance that the constitutional failings of Nebraska’s statute can be easily fixed, ante, at 5, is illusory. The majority’s insistence on a health exception is a fig leaf barely covering its hostility to any abortion regulation by the States–a hostility that Casey purported to reject."