BOB ABERNETHY, anchor: This coming week (November 8) before the Supreme Court, arguments on what many see as a major effort to restrict abortions. It is a challenge to the constitutionality of a law passed by Congress three years ago called the Partial-Birth Abortion Ban Act. Tim O'Brien reports.

UNIDENTIFIED MAN: Stop the killing, Leroy.

TIM O'BRIEN: The challenge to the federal law was brought by Dr. Leroy Carhart, who runs this abortion clinic just outside Omaha, Nebraska. He's grown accustomed to hecklers whenever he shows up for work.

UNIDENTIFIED MAN: All they want to do is live, Leroy. Stop the killing.

O'BRIEN: But Carhart is also a hero, a "champion of choice" to abortion rights advocates. Six years ago, it was Carhart who successfully challenged a Nebraska state law very similar to the federal ban on so-called "partial-birth" abortion now before the Supreme Court.

Opponents of the law also challenge its title. They say the words "partial-birth" suggest the law is aimed at late-term abortions when the fetus is viable, a ban even Carhart could support.

Dr. LEROY CARHART (Abortion & Contraception Clinic of Nebraska): Every state that I practice in, which is eight states right now, have laws against late-term abortion. To my knowledge, they have never been challenged. Certainly states that I don't practice in have these laws.

O'BRIEN: Do you oppose those laws?

Dr. CARHART: Not at all. I think they're made for the good of the fetus. I think they're made for the good of the welfare of the community.

O'BRIEN: In throwing out the Nebraska state law six years ago, the Court observed that it did not have an exception when the health of the mother was at risk. It also found the law so broad that it unconstitutionally outlawed commonly used procedures in second trimester abortions. That might have been the end of it -- but it wasn't.

President GEORGE W. BUSH: I ask you to protect infants at the very hour of their birth and end the practice of partial-birth abortion.

O'BRIEN: Three years later, President Bush and the Republican-controlled Congress pushed through legislation almost identical to the Nebraska law that the Supreme Court had rejected.

Within hours of the bill's being signed, a federal court blocked enforcement because the new federal law -- just like the Nebraska law before it -- failed to include an exception to protect the mother's health.

The principal sponsor of the ban said no exception was needed -- that Congress held hearings and made findings that the health of the mother is never at risk in partial-birth abortions.

Sen. RICK SANTORUM (R-PA): This procedure is never, and I underscore the word never, never medically necessary to preserve the health of the mother. Never.

O'BRIEN: Santorum and other defenders of the federal ban say the Supreme Court should defer to the findings of Congress on whether a medical exception is necessary. The lower courts did not.

VICKI SAPPORTA (President, National Abortion Federation): Three challenges were brought against the federal abortion ban, and in each one of those three cases, the judges in those cases decided that the government's findings were incorrect and that the government did not find correctly, and that, in fact, a health exception was necessary.

O'BRIEN: The medical community is divided. The American Medical Association says it does not condone partial-birth abortion. But the American College of OBGYNs has urged the Supreme Court to reject the federal ban, writing in a friend of the court brief that doctors and patients, not lawmakers, are the appropriate parties to determine the best method of treatment.

Dr. CARHART: I think that, as a physician, I am obligated to tell my patients all the acceptable options that they have. I think it's up to my patient to be able to make a decision where she thinks she needs to go with all the information she has. If she wants to take in all the information from everybody else, including Congress, that's fine. But ultimately the decision has to be the patient's, without being encumbered by anyone.