Though the two sides disagree on the effect of upholding the Pennsylvania law, they agree that the current court is virtually certain to approve the new abortion restrictions.
Only two of the nine justices are known to support the fundamental right to abortion: Harry A. Blackmun, the author of the 1973 Roe decision, and John Paul Stevens.
Four members of the court have said that they would overturn the Roe decision: Rehnquist and Justices Byron R. White, Antonin Scalia and Anthony M. Kennedy.
If either of Bush's two conservative appointees to the court--Justices David H. Souter or Clarence Thomas--were willing to join such an opinion, it would overturn the right to abortion. States would then be free to ban abortion.
The only woman on the court, Justice Sandra Day O'Connor, has criticized the Roe decision, but also has been unwilling to overturn it.
In 1989, when the justices last considered a major abortion case, O'Connor was the swing vote. In that case, Webster vs. Reproductive Health Services, the court upheld a series of Missouri restrictions, including a ban on abortions in public hospitals and clinics. Bush Administration attorneys had urged the court to write an opinion that overturned Roe vs. Wade entirely but O'Connor refused to go along with such a sweeping ruling.
But the retirements of Justices William J. Brennan and Thurgood Marshall, both of whom were strong strong supporters of Roe vs. Wade, and their replacements by Souter and Thomas have given the conservative wing of the court a commanding majority.
Indeed, abortion rights advocates labeled the Supreme Court a lost cause Tuesday and said that they plan to spend more time seeking passage in Congress of a national Freedom of Choice Act. This proposal, strongly backed by Democratic leaders, would write into federal law a guarantee that pregnant women could choose abortion.
ACLU officials conceded that Bush would be likely to veto such a bill. All five of the leading Democratic presidential candidates have said that they would protect a woman's right to choose abortion.
The impact of the court's ruling on the fall elections would depend on how broadly written it is, political analysts said. At a time when voters are focusing on the economy, polls show other issues, including abortion, have become less important.
As a result, only a fairly dramatic decision by the court would influence substantial numbers of voters, according to Democratic analyst Greg Schneiders.
Times staff writer David Lauter contributed to this story.
Abortion Control Act Provisions
The Supreme Court will consider five provisions of the Pennsylvania Abortion Control Act of 1989:
INFORMED CONSENT: Doctors may perform abortions only on women who have given a "voluntary and informed consent." This means that 24 hours before the procedure, the doctor must tell the woman of "risks and alternatives." In addition, the doctor must tell the patient of "the probable gestational age of the unborn child."
MEDICAL EMERGENCY: Doctors may ignore these steps and perform an emergency abortion only to "avert her death" or to head off "irreversible impairment of a major bodily function."
PARENTAL CONSENT: A doctor may perform an abortion on a pregnant woman who is under age 18 only if at least one of her parents has consented.
REPORTING REQUIREMENTS: Doctors must file reports to the state on each abortion performed, including the "type of procedure performed" and the "gestational age of the unborn child."
SPOUSAL NOTIFICATION: A doctor may not perform an abortion on a married woman without a statement from her certifying that she has informed her husband of her plans. This requirement may be waived if the spouse cannot be located, is not the father or has assaulted his wife or is "likely" to do so. The U.S. 3rd Circuit Court of Appeals upheld all of the provisions, except the spousal notification requirement.