I have just printed the Supreme Court's decision this morning in Gonzales v. Carhart, rejecting a facial challenge to the congressional ban on partial birth abortions. It's a 5-4 decision with Justice Kennedy joining Chief Justice Roberts and Justices Alito, Scalia and Thomas. There is a blistering dissent by Justice Ginsburg.
I have only skimmed it. It does not completely resolve the question of partial birth abortions because the majority opinion leaves open the possibility of an "as-applied" challenge. Here that would most likely involve an actual case in which a doctor claimed that the procedure was medically necessary to avoid a significant health risk to the mother. Justice Kennedy seems to have concluded that there is medical uncertainty regarding whether the procedure is ever necessary and, in the face of that uncertainty, Congress had the authority to act. But Kennedy, at least, left open the possibility that the result may be different if, in a particular case, it can be shown that "in discrete and well-defined instances" the procedure must be used.
This does seem to overrule the approach taken in Stenberg v. Carhart seven years ago in which the majority seemed to say that the procedure must be allowed as long as there was "substantial medical authority" that banning the procedure could endanger a woman's health.
What has changed? Justice Alito has replaced Justice O'Connor. Professor Marty Lederman, writing on ScotusBlog, takes the opportunity to remind us of the decisions in which Justice O'Connor cast the deciding vote.
The majority opinion assumes the continued viability of the court's current jurisprudence on abortion as expressed in the joint opinion in Planned Parenthood v. Casey, i.e., that there is a constitutional right to an abortion. Justice Thomas, joined by Justice Scalia, wrote separately to reiterate that he (and Scalia) do not accept that jurisprudence. Chief Justice Roberts and Justice Alito did not join that concurrence. I do not read anything into that. At this point, there appear to be five votes on the court to continue the Roe regime, two to end it, and two who have not weighed in.