As Congress prepares to probe Supreme Court nominee John Roberts's leanings on this or that constitutional question, it should not overlook a larger concern about the Supreme Court as an institution. The court is in desperate need of reform; it has become increasingly isolated, imperious and opaque.

This is no accident. It follows largely from the assumption, nurtured by the media and embraced by the justices, that they hold "lifetime" appointments. But it is time to rethink this assumption. And there is some reason for optimism that Roberts himself might agree and make a unique personal contribution to bringing about overdue change.

The power of Supreme Court justices today is epic in scale. The cases they hear involve the most difficult and contentious questions before the nation. An alphabetical list would begin with abortion and proceed through campaign finance, church-state relations, euthanasia, pornography, presidential selection and voting rights. And once appointed and confirmed, the members of the court who engage these momentous issues are able to do so for as long as they please.

Yet the power this gives them is not matched by humility, nor leavened by sensitivity to the democratic values of accountability and transparency. Consider:

Long after Congress opened its chambers to the electronic media, the Supreme Court continues to refuse to allow television, still cameras and tape recorders to record arguments and other proceedings. The justices limit their public appearances and, even more so, media interviews and exchanges. Justice Antonin Scalia has notoriously refused to allow his public speeches to be filmed, photographed or tape recorded, and last year, marshals actually wrestled a recorder away from a reporter at one of his public appearances. The public, meanwhile, is kept at a safe distance from the court: Visitors wishing to see oral arguments are ushered in and out of the court in brief shifts. These behaviors all assume that the Supreme Court as an institution and the justices individually have the right to tell the people only what they choose.

How did the third branch of government come to assume such an imperious, undemocratic attitude? A significant part of the answer lies in the ability of justices to stay on the court as long as they themselves see fit. We think of appointments to the court as lifelong, but Article III of the Constitution says nothing about "lifetime appointments." It provides that justices (and judges on the lower federal courts) "shall hold their Offices during good Behaviour"; its purpose is to isolate justices from political pressures.

Many early justices served reasonably brief tenures. The first chief justice of the United States, John Jay, served five years. By comparison, the fourth chief justice, John Marshall, remained on the court for 34 years. Marshall is generally considered the greatest chief justice. But his decision to stay on, unlike George Washington's choice to step down after eight years as president, set the court and the presidency on divergent paths, to the discredit of the court. We are paying for Marshall's precedent today, just as we are the beneficiaries of Washington's foresight.

Supreme Court justices are serving ever longer. Justices who left the court from 1971 to 2000 served an average of 25.5 years. The current chief justice has served for 33 years. Eighty-four-year-old John Paul Stevens has served for 29. Sandra Day O'Connor retired after 24. John Roberts is 50, and if he serves until he is Stevens's age, he will be on the court until 2039. There is no comparable political position in this country that allows a powerful officeholder, unless called to the next world, to determine his or her own length of service in this one.

Why do justices grip the gavel for dear life? Some argue that longevity serves the court well, enriching its work with the vast experience that indefinite terms make possible. But in our system of government, we normally constrain great power with limits rather than license its indefinite exercise. And while the work of the court is challenging, the country teems with lawyers and jurists of great ability who could serve on it with distinction.

The true reasons for the justices' refusal to serve limited terms are simple. First, the work is manageable. In contrast to the lower federal courts, which must hear all cases that are properly filed, the Supreme Court chooses its own docket. While the lower federal courts are in session year-round, the Supreme Court usually hears cases only from October through June. Moreover, the number of cases the court hears and decides has declined sharply in recent years. Three decades ago, it decided well over 100 cases; by the 1990s, its caseload had dropped to less than 80. The court produced 71 signed opinions in 2002 and 73 in 2003. Bright law clerks supply the research and the drafts.

Whether cases are hard or easy, a justice's jurisprudence -- the way he or she instinctively leans on any given issue -- is quickly set, usually within a year or two. For example, once a justice decides that a woman has the fundamental right to an abortion, variations on that issue -- whether parents must be notified, or whether there must be a cooling-off period between the decision and the abortion -- take most justices little time to decide. To be sure, the occasional odd case arises: a Bush v. Gore, for instance. But these are rare.

Under these conditions, there is little reason for anyone to voluntarily relinquish this powerful, coveted and comfortable job. Observers troubled by this state of affairs have proposed various possible solutions, from an amendment to the Constitution to legislation suggested by a group of law professors that would limit the justices to terms of 18 years. But the likelihood of any constitutional or legislative solution being enacted is small: Few in Congress have the appetite for the long, grueling and uncertain battle that would be entailed.

Yet there is still much that could be done to make the court far more democratic in tone and substance and to discourage justices from staying at their posts indefinitely. Congress, for instance, could cut the Supreme Court's budget until it agrees to allow cameras and audio equipment into all federal courtrooms, thus taking a modest step toward a healthier relationship with the public -- and toward a healthier measure of accountability.

But the most important and most dramatic step the president and Congress could take is to seek a commitment from a Supreme Court nominee that he or she will serve a sensibly limited period of time. The president could announce such a commitment when he introduces the candidate to the media. The Senate Judiciary Committee could ask the nominee about his views on longevity and also seek a commitment, even to a range of years. Any justice who hopes that with the passage of time such an exchange would be forgotten would likely be disappointed. Over time, a custom or expectation would develop. No law would be necessary to assure that justices act in the socially accepted fashion, just as no president served more than two terms for almost 150 years after Washington.

Roberts's nomination may be just the right moment to try this approach. He wrote favorably about term limits for federal judges in 1983. "Setting a term of, say, 15 years would ensure that federal judges would not lose all touch with reality through decades of ivory tower existence," he wrote in a memo addressing a proposed constitutional amendment to limit judges' terms. Roberts appreciated that the case for term limits was strengthened by the enormous power of the federal judiciary, which "today benefits from an insulation from political pressure even as it usurps the roles of the political branches."

In reconsidering lifetime service, it would make no sense to make an exception of the most powerful federal court of all. So it would be fair to ask Roberts whether he would be prepared to commit to a term shorter than a lifetime, set by some consideration other than personal preference. The question does not call for "prejudging" a particular constitutional issue, and so does not justify the standard evasive maneuver. The answer he offered would be telling, particularly in light of his previous views on the subject.

It is long past time that the media, the Congress and the executive branch act to remind the court, and those who would serve on it, of its position in our governmental scheme; to affirm that the public has a strong and legitimate interest in how the court behaves; and to demand the transparency, accountability and respect for limits that are a hallmark of powerful public institutions in our democracy.

Congress can start with a simple question.

Author's e-mail: RBauer@perkinscoie.com

Robert Bauer practices political law in the Washington office of Perkins Coie and writes on the subject at www.moresoftmoneyhardlaw.com.

Long-lived precedent: John Marshall served as chief justice from 1801 until his death in 1835, setting the pattern of lifetime tenure for Supreme Court justices.