WASHINGTON - For voters who need a reminder of the central role that the Supreme Court plays in political life, the next few weeks could be a wake-up call.
Just consider the hot-button issues the justices are about to rule on: Should so-called partial-birth abortion be banned? Can gays be barred from the Boy Scouts? What are the constitutional limits on public-school prayer, on police authority, on aid to parochial schools, and on patients' power to sue health maintenance organizations?
Each of the rulings, expected by the end of June, is likely to come down to a close, controversial vote - the nine-justice court consistently splits 5-4. Together the cases promise to increase the pressure on presidential candidates, jostled by groups on the right and the left, to pledge themselves to future nominees who will swiftly shift the court's ideological tilt.
It is not automatic that the next president will get to change the court's makeup, since Supreme Court justices can serve for life. But because three of the nine are 70 or older (John Paul Stevens is 80) and none has retired for six years, the odds are high that either Al Gore or George W. Bush will have the opportunity to appoint one or more justices and reshape the court for years to come.
''For those who are feeling this election doesn't much matter, who think it's a choice between Tweedledum and Tweedledee, the court is the reason to care,'' said Lois Williams, senior counsel for litigation at the Washington Lawyers Committee for Civil Rights, a liberal advocacy group.
Gore, saying that the next president could nominate three members of the court, has pledged to choose justices who believe the Constitution is a ''living and breathing document'' that the court can and should adapt to changing times, and who will uphold Roe v. Wade, the 1973 landmark ruling that legalized abortion.
The Texas governor, pressed by some of his GOP primary opponents to reject any court prospect who would not overturn Roe, has said he would not apply an antiabortion litmus test. But he has told Republicans that they can rest assured he will appoint justices who ''will strictly interpret the Constitution'' and model themselves after conservative Justices Antonin Scalia and Clarence Thomas.
For most Americans, debates about judicial philosophy often seem esoteric. Most do not follow the court closely, recognize the Supreme Court justices' names, or even know how many there are.
But for religious conservatives who want the federal courts to be on the front line of the culture wars, or for liberal activists who believe the courts should be the fulcrum of social change, the nominees of the next man in the White House make a huge difference.
By the time he leaves office, President Clinton will have appointed two Supreme Court justices, which is the average, and will have filled about half of the rest of the federal judiciary, the US district and appeals courts, where 99 percent of all cases are decided. The other half are almost all Republican appointees, setting the stage for the next president to tip the balance on those courts, too.
On the campaign trail, Gore often brings up the Supreme Court as he speaks of the need to protect abortion rights as he woos undecided women voters.
Bush, who wants to win over the same women while not alienating conservatives, rarely volunteers his views on Roe or on remaking the high court.
Abortion is just one of the major issues the court inevitably will visit in terms ahead. Also on the near agenda are same-sex marriage and domestic-partnership benefits, bioethics, gun control, school vouchers, and privacy and intellectual property on the Internet.
The court has seemed ready to tackle the tough issues. The current term has been unusually full of politically sensitive cases. Since January, the Supreme Court has affirmed the rights of parents over grandparents, lifted restraints against sexually explicit programming on cable TV, and rejected the Food and Drug Administration's effort to regulate tobacco.
In two states-rights cases, the court barred state employees from suing for age discrimination and threw out part of the 1994 Violence Against Women Act that allowed rape victims to sue attackers in federal court.
In all but the parents' rights case, which was decided by a majority of six justices, the court split 5-4.
Generally, the justices align like this: Thomas and Scalia anchor the conservative wing and are often joined by Chief Justice William H. Rehnquist. Justices John Paul Stevens, Ruth Bader Ginsburg, and Stephen G. Breyer typically vote together as the liberal-moderate bloc, and are frequently joined by Justice David H. Souter. The centrist conservatives who tend to tip the balance are Sandra Day O'Connor and Anthony M. Kennedy.
''If we get another Scalia or Thomas, we are courting disaster,'' said Ralph Neas, president of People for the American Way, a liberal civil rights group that will hold debates and town meetings this fall to raise awareness of the Supreme Court. ''We are just one election away, and one or two new justices away, from the civil and constitutional rights we take for granted being eroded or eliminated overnight.''
The National Abortion and Reproductive Rights Action League, which has endorsed Gore, is planning a nationwide radio and television advertising campaign, plus get-out-the-vote drives in 15 states, including Massachusetts, to warn of the threat to Roe if the country elects an antiabortion president.
Conservative groups are energized, too, particularly the Christian right, which looks to the Supreme Court for social policy on school prayer and religious-school vouchers. The National Right to Life Committee is so intent on overturning Roe by getting a Republican in the White House that it has enthusiastically endorsed Bush, despite his refusal to impose an abortion litmus test on judges.
Former GOP presidential candidate Gary Bauer says that without that commitment, he cannot be sure about Bush. Bauer notes that Bush's father appointed Souter, the New Hampshire judge who served on the US Court of Appeals in Boston and who turned out to be a bitter disappointment to social conservatives.
''There is not one judicial appointment the Democrats have to apologize for, but - oops! - it happens in my party all the time,'' said Bauer, who, as head of the Campaign for Working Families, sends out 10,000 e-mails to conservative activists every day, often on the subject of abortion. ''If George Bush nominates three Scalias, he will have an honored place in the great conservative history book. If he nominates a couple of Souters, he will guarantee the culture will move against us.''
The judicial appointments by Bush as Texas governor and by the Clinton-Gore administration show some similarities: They are characterized by gender and racial diversity and moderate ideology.
At the end of 1999, Clinton had appointed 339 federal judges; 100 of them were women, representing 49 percent of all females on the federal bench, and 105 were black, Hispanic, or Asian-American, making up 48 percent of all nonwhite federal judges.
Bush, who named a woman, a Hispanic, and a disabled lawyer to the Texas Supreme Court, has generally won praise at home for high-caliber, moderate-conservative appointees. But Anthony Champagne, a professor of government and politics at the University of Texas at Dallas, says one should not assume the same pattern would prevail if Bush becomes president.
''The political pressures and media attention on him will be so much different on the national level,'' Champagne said. ''There will be so many more people he has to please.''
With their views at odds on a host of issues, Bush and Gore would certainly be philosophically inclined - and lobbied by polar-opposite interest groups - to appoint very different kinds of judges to the federal bench.
The reality, however, is that to avoid a partisan confirmation brawl in the Senate, presidents are tempted to pick judges with little or no record to attack, and once on the bench, their views can be a big surprise. And, judges grow and change on the job.
The late Justice William J. Brennan, a leading liberal on the court, was appointed by President Eisenhower, a Republican. The late Justice Harry A. Blackmun, who wrote the Roe opinion, was appointed by President Nixon. Souter, who came to President Bush's attention via John Sununu, the former Republican governor of New Hampshire, chose an independent path very soon after he was confirmed.
''Personally, I think [Souter] was cleverly deceptive,'' said David O'Steen, executive director of the National Right to Life Committee. ''I believe he held himself forward to be a conservative jurist, which he has proven not to be.''
