IT couldn't have been a reassuring day for Colorado attorney Timothy Tymkovich. He had just begun arguing the first Supreme Court gay-rights case in a decade when skeptical queries shot out from the two people he least wanted them from: Justices Anthony Kennedy and Sandra Day O'Connor.
Mr. Tymkovich, Colorado's solicitor general, was asking the court to uphold a popular referendum outlawing legal protections for homosexuals. He wanted the support of the two justices whose votes increasingly determine the direction of the nation's highest legal body. He didn't seem to get it.
Like most everyone present, Tymkovich expected the sympathy his cause received from Justice Antonin Scalia, the court's leading conservative ideologist. He also anticipated the slightly hostile questions from Justice Ruth Bader Ginsburg, a leading civil libertarian.
But in a court often described today as polarized, Kennedy and O'Connor wield the all-important ''swing vote'' and may determine how far right the court will go.
''Kennedy and O'Connor hold the balance of power on this court,'' says James Simon, dean of New York University Law School. ''They are pivotal, and it will be left to them to decide cases like Colorado.''
Battle lines on the high court have hardened recently. Last spring, in strongly contested (5-to-4) decisions, the court issued its most conservative rulings in years. It was Kennedy and O'Connor who cast key votes to curb desegregation, affirmative action, and - in the first such ruling in 60 years - limit the power of Congress.
In general terms, Justices John Paul Stevens, Ginsburg, and Stephen Breyer are moderate centrists. Usually they are joined by David Souter, who has become the Court's intellectual counterweight to the three ideological conservatives on the hard right: Chief Justice William Rehnquist, and Justices Scalia and Clarence Thomas.
That leaves Kennedy and O'Connor, both moderate conservatives appointed by President Reagan. Court scholars are divided over whether the two swing voters are today the driving force on the bench or are merely applying brakes to a conservative juggernaut.
''They are at center, but it is the furthest right of center you can imagine,'' says David Cole of Georgetown Law School in Washington, D.C.
Vision of limited court role
Both Kennedy and O'Connor are strongly committed to the vision of a limited role for the courts and the federal government. O'Connor particularly, coming from Arizona, believes firmly in a strong Western conservative tradition of trusting local decisionmaking.
Yet unlike the ideological conservatism of Rehnquist, Scalia, and Thomas, the two swing voters have carved out a moderate position on civil rights and liberties. The hard right would have overturned Roe v. Wade, for example, which guarantees the right to choose an abortion. O'Connor and Kennedy resisted that pressure in the 1992 Casey decision, casting the decisive vote in a case that would have begun to roll back Roe.
''They understand the court's special role in protecting rights,'' argues Mr. Simon.
This role was evident in Tuesday's questions, when Kennedy flatly told Tymkovich that ''I've never seen a statute like this.'' O'Connor wondered aloud whether or not homosexuals would be allowed to check out library books in the cities of Aspen, Denver, and Boulder.
Of special importance to both justices, but particularly O'Connor, is what jurists call stare decisis - hewing to previous rulings as much as possible, even if a justice doesn't like the particulars in a case. The practice protects the court from swinging or changing radically every time a new justice is sworn in, scholars say.
It was stare decisis, for example, that came into play in Casey. At the start of the 1992 term, sources say, Kennedy and O'Connor were both considering a ruling that would restrict Roe. (According to Judge Robert Bork, Kennedy had made it clear prior to being nominated that he would vote to overturn Roe.) Yet David Souter, in private meetings with the two justices, made a compelling case not to do so on grounds of stare decisis and civil order.
Despite similar views, however, the two swing voters are quite different in style and approach.
O'Connor has a reputation inside the court for sticking with her positions.
One colleague says that if O'Connor has made up her mind, ''it doesn't matter if you show her 25 law-review articles, you might as well go on vacation.''
Kennedy, by contrast, has a reputation for being easily swayed by his law clerks and for changing his vote. The practice privately exasperates both liberal and conservative justices. ''He likes being courted by both sides,'' says the former law clerk of a liberal justice in a disparaging tone.
Kennedy has moved both directions on First Amendment questions. In 1990, he wrote a broad opinion on religious freedom, arguing that the government should give more ''latitude in recognizing and accommodating the central role religion plays in our society.'' Yet in 1993, he stuck with the court's school prayer precedent on separation of church and state - a decision that enraged Scalia, who said the opinion read like ''amateur'' psychology.
Still, while much attention is paid to the role of the two swing voters, some court-watchers say Chief Justice Rehnquist silently wields the most powerful influence on the court.
Rehnquist's agenda since 1971 has included carrying out more death penalties, rolling back affirmative action, lowering the wall between church and state, and enhancing states rights. Kennedy and O'Connor may simply be centrists in a court that is inexorably moving further to the right.
Certainly the character of the last term bears the mark of the Rehnquist agenda; there were, for example, more death penalties allowed by the court in the last term than in any since the early 1960s.
This term, the court's rulings in the Colorado case and two upcoming cases will challenge further the practice of creating political districts for minorities and test if it is Rehnquist or the swing voters who represent the high court's center of gravity.