Listen closely around official Washington this week, and you can hear a very subtle sound. It's people holding their breath. The latest Supreme Court term is drawing to a close. There are important rulings on affirmative action and gay rights still outstanding. But the decision that the city is really waiting for will be handed down by one man alone. At age 78, with a bad back, a Republican in the White House and his own powerful legacy firmly in place, Chief Justice William Rehnquist may decide this would be the perfect time to retire. If he steps away now, he ensures that his successor will be chosen by a Republican President — and that it will happen before the hurly-burly of an election year.

But it's been so long since we have had an old-fashioned confirmation bloodletting, you could almost forget the foul mood that overtook the U.S. during the fights over Robert Bork and Clarence Thomas. Washington was so shell-shocked by the Thomas battle that people were intent on turning the next Supreme Court vacancy, in 1994, into a milder affair. And Stephen Breyer's confirmation process proved to be a breeze.

If Rehnquist does step down, don't expect a bipartisan buddy system to play much of a part in choosing his successor. George W. Bush has already parried a request made this month by the ranking Democrat on the Senate Judiciary Committee, Patrick Leahy of Vermont, for a fuller dialogue between the White House and Democrats on any high-court nominees. And if Sandra Day O'Connor should also retire this year, the struggle over her replacement could be judicial Armageddon, because O'Connor and Anthony Kennedy have been the court's crucial swing votes. If Bush could replace her with a more consistent conservative, Roe v. Wade itself would be in jeopardy.

But whenever Rehnquist departs, he can do it in the knowledge that the court he led is likely to be remembered as one of the most influential in American history — and not just because of the 5-4 ruling in Gore v. Bush that effectively gave the 2000 election to the man who lost the popular vote. Rehnquist has spent more than 31 years on the high court, 17 of them as chief. That has been time enough to see the court, and much of the nation, come around to the conservative views that once made him so isolated that he kept a Lone Ranger doll on his mantelpiece, symbolic of his many solitary dissents.

Especially after Antonin Scalia and Clarence Thomas joined the court, giving him two firm allies, Rehnquist spearheaded a determined effort to stem — and roll back — the liberal advances made by the Warren and Burger courts. In many ways it worked. Affirmative action is more difficult to implement now. The barrier between church and state is more porous. Convicted criminals have a much harder time getting multiple appeals heard in federal courts. But Rehnquist's most enduring legacy is in the less visible but crucial area of federalism — the balance of powers between Washington and the states. The Rehnquist court has sharply trimmed the power of Congress to tell the states what to do. His abiding belief that the Constitution was created to restrain the reach of the Federal Government has been his mantra as Chief Justice. Rehnquist did not always get his way: not on Miranda rights, which he opposed (though he wrote the 2000 opinion upholding them, acknowledging that the matter was now settled law), or on Roe v. Wade, in which he was one of two dissenters. But the days are long over when liberal groups could count on the court to carry forward their agenda.

Disaffirming Affirmative Action
The signal achievement of the Warren court was its unanimous ruling in 1954's Brown v. Board of Education that segregated public schools were unconstitutional. During Rehnquist's Senate confirmation proceedings in 1971, it emerged that in the early 1950s, while he was a clerk for Supreme Court Justice Robert Jackson, Rehnquist had prepared a memo defending the old and reviled "separate but equal" doctrine. Rehnquist insisted that he had merely been distilling Jackson's views. But the court he eventually led made job-discrimination claims harder to win and rejected the use of statistics showing that the death penalty in Southern states was imposed in a racially biased way.

As for affirmative action, it was Rehnquist's court that ruled in 1995 that preferential treatment based on race in government programs is almost always unconstitutional. This was a legal earthquake, throwing into doubt most of the government's affirmative-action programs. A secondary tremor could come this week in a pair of University of Michigan cases involving the use of race as a factor in the admissions process. It's true that some colleges and universities around the country are already using creative ways of getting around a possible affirmative-action ban. But if the court bars or narrows affirmative action in admissions policies, it will nonetheless put a chill on many of those nontraditional efforts, while public schools nationwide will have to throw out the traditional ones as well. "The court has shown a distinct distaste for race-based remedies," says A.E. Dick Howard, a professor at the University of Virginia School of Law. "No matter what it decides in the Michigan cases, it has made it harder across the board to have affirmative action."

Repealing the Right to Appeal
When Rehnquist first arrived in Washington in 1952 to clerk for Jackson, he was already a law-and-order hard-liner. "Ivory tower jurisprudence," he wrote in one memo to Jackson, "has weakened local law enforcement." In the late 1960s, as head of the Justice Department's Office of Legal Counsel, Rehnquist gladly defended the legality of preventive detention and "no knock" searches. One of Rehnquist's victories on the court has been to limit sharply the opportunities for state prisoners to petition federal courts to hear appeals of their convictions.

For years, death-row inmates filed appeal after appeal, allowing them to postpone execution again and again. Rehnquist was one of four dissenters in the 1972 decision striking down state capital-punishment laws because they were administered arbitrarily. Four years later, the court once again permitted executions. But Rehnquist soon became frustrated because so many defendants delayed their sentences using federal appeals. With a 1989 decision, Teague v. Lane, as well as others in which Rehnquist was in the majority, his court eroded the ability of convicts to file appeals. Finally, in 1996, Congress followed his lead, rewriting federal law to incorporate Rehnquist's thinking on the appeals question. "The new standard makes it almost impossible for someone who has been convicted in state court to get to a federal court," says Richard Fallon, a professor at Harvard Law School.

But once again Rehnquist was unable to get everything he wanted. In 2002, for instance, the court ruled that states could not execute the mentally retarded. In that case Rehnquist even returned to Lone Ranger status: he was the sole dissenter.

Giving God a Hand
Rehnquist once wrote that the separation of church and state was "a misleading metaphor based on bad history." To his way of thinking, the framers of the Constitution intended merely to forbid the establishment of an official state religion, as exists in England. He has had a mixed record in getting a majority of the court to sign on to this view. The court has disallowed student-led prayer and graduation prayers by a clergyman — both of which he supported. But he played a pivotal role in allowing tax money and other public resources to be used for purposes that promote religion. In 1995 he was in the majority that ruled 5 to 4 that a school could not deny student-activity funds to a Christian student newspaper when it provided such funds to other student publications. In last year's important school-vouchers decision, Zelman v. Simmons-Harris — a 5-4 ruling written by Rehnquist — the court allowed needy families to use vouchers for religious as well as secular schools.

Federalism Unbound
After the hot-button issues of race, crime and religion, the question of federal-state power sharing may not stir the blood. But it goes to the heart of the fundamental political struggles of the past century. The civil rights legislation of the 1960s, for instance, often used the power that Congress was granted by the Constitution "to regulate commerce ... among the several states" as the means to legitimize federal mandates on racial integration. To Rehnquist, this is a perversion of the Constitution, and he has been on a three-decade-long quest to rein in federal power. As early as 1975 he was arguing — in another lone dissent — that states could resist a mandate from Congress by asserting that the framers believed in much greater state sovereignty. And here he has made the most headway, getting a majority of Justices to agree with him that a variety of federal laws overstepped the limits of congressional power.

Under his leadership, the court has struck down 28 laws in six years — a considerable number, notes Georgetown law professor Neal Katyal, when you consider that in the nation's first 200 years the court struck down only 127. Among these overturned laws was one making it illegal to have a gun within 1,000 ft. of a school zone and others allowing states to be sued for discrimination on the basis of age, disability and other criteria. To Rehnquist's critics, the large number of overturned laws made it appear that he was practicing the same judicial activism for which conservatives attacked the Warren court. "This is not so much the court setting itself as the protector of the states," says David Garrow, a law professor at Emory University. "It's the court setting itself up as the regulator of Congress's legislative power." To which Rehnquist would say, "Exactly." That is precisely the job of the court if you think the power of the Federal Government has been growing beyond the boundaries set by the Constitution.

Rehnquist always knew where he wanted the court to go. But in recent years it may have become less important to him how the court got there. Even as far back as the late 1980s, a conservative clerk heard him say at lunch, "I used to worry about every little footnote. Now I realize you just need five votes." There's probably no decision where the marshaling of five votes — rather than the legal reasoning behind them — was more critical than the case of Bush v. Gore. At the end of five tense postelection weeks, the court issued an unsigned 5-4 opinion that stopped the recounting in Florida, throwing the election to Bush. Rehnquist worked intently behind the scenes to assemble a majority consensus. The underpinning of that decision — an equal-protection argument that would normally be anathema to conservatives — was described even by many Republican lawyers as being weak and unsustainable as a precedent.

The Conservative Holy Grail?
As with any court, what Rehnquist has built could be torn down over time, but it would not be a day's work. "His doctrines are quite entrenched," says Chicago law professor Cass Sunstein, "both because the court respects its own precedents and because there aren't any liberals on the bench. There are moderates, but nobody is leading a countercharge." If anything, it's more likely — particularly if Bush is re-elected — that a conservative will also replace liberal John Paul Stevens, 83. That would give conservatives their Holy Grail, an unstoppable majority. Such a majority would certainly consolidate and enlarge Rehnquist's legacy after he leaves the court. But whenever Rehnquist retires, he will leave Washington a smaller place for his having been there. From the day he arrived, that was just what he had in mind.

• Richard Lacayo and Viveca Novak