BOB ABERNETHY, anchor: The U.S. Supreme Court handed down a landmark abortion ruling this week. In a 5-to-4 decision, the Court upheld a federal law that outlaws the so-called partial-birth abortion procedure. Abortion opponents praised the ruling; pro-choice advocates were outraged. Tim O'Brien, a distinguished visiting professor at Nova Southeastern University Law School in Florida is here with us.

Tim, welcome. Exactly what did the Court say?

TIM O'BRIEN (Visiting Professor, Nova Southeastern University Law School): The Court did acknowledge that women have a constitutional right to choose abortion, but also that the government has a legitimate interest in protecting potential human life. And in this case the government's interest outweighed the woman's right to choose.

ABERNETHY: All five of those in the majority on the Court are Catholic. If you were to ask them whether their religion had anything to do with their decision, what do you think they would say?

O'BRIEN: Well, they might acknowledge that we're all affected by our backgrounds, our environment, but I'm sure they would say that religion had nothing to do with it -- that it was their interpretation of the Constitution, how they viewed the law.

ABERNETHY: So there's no change in a woman's right to have an abortion except she can't have it anymore using this partial-birth abortion procedure. And there's no ban on lots of other procedures that have been used. So why are the pro-choice people so upset?

O'BRIEN: Well, I think in large measure because just a few years ago the Supreme Court rejected a similar ban on a 5-to-4 vote. The law was very much like this one. It did not have an exception for when the health of the mother was at risk. This law did not have an exception for the health of the mother.