The Supreme Court will resume its formal duties in just over three weeks, facing a period of uncertainty — perhaps lasting for several months — in the wake of the death of Chief Justice William H. Rehnquist Saturday night. The Court will operate as close to normal as possible, with the senior Associate Justice, John Paul Stevens, in charge. Stevens is not expected to take any significant initiatives without fully consulting his colleagues, since he holds no formal position other than his own Associate Justiceship. The law does not provide for an “Acting” Chief Justice.

A Court of seven Justices can function fully, since the law specifies that it takes a quorum of six to take official action as a Court. The Court is scheduled to begin on Monday, Sept. 26, to review new cases that have developed during its summer recess. Public hearings will begin as scheduled on Monday, Oct. 3. At this point, it is uncertain whether Judge John G. Roberts, Jr., will have been approved by the Senate as a new Associate Justice by the time of either the Sept. 26 Conference or the beginning of hearings Oct. 3. If approved, he would take the seat left by the retirement of Justice Sandra Day O’Connor.

Because the existence of two vacancies, rather than one, is expected to affect more profoundly the future of the Court, the process could become fairly lengthy. Although the White House and Senate Republican leaders are likely to stress the need to fill the vacancies as soon as possible, the difficulties that could arise in the process — especially, political difficulties — may not be resolved easily or quickly.

It is possible, of course, that the President could provide a temporary replacement for Rehnquist. That could occur if the Senate were to take a recess during the time that the succession to Rehnquist’s seat is unfolding. It would be likely, though, that the President would want to give such a “recess appointment” to the individual he planned to name as a permanent replacement, so the selection of even a “recess Chief Justice” may not be done swiftly. A recess appointee could serve until the end of the current Congress — that is, until January of 2007.

Even if the President were to elevate an existing Associate Justice to the Chief Justiceship, that would still require a new nomination and Senate approval. The Constitution does not provide for a simple promotion to the Chief Justiceship outside the normal requirements for an appointment to the Court. At this stage, it seems that the President probably would not select a new Chief Justice from among the present Associates: the only two possibilities, Justices Antonin Scalia and Clarence Thomas, would encounter especially strong opposition in the Senate.

No one doubts that the President would use the new opportunity that results from Rehnquist’s death to name a reliable conservative to the Court. He has already demonstrated that he does not regard his desire for conservative jurists as subject to any need to accommodate the opposition that might be predicted from Senate Democrats. Indeed, he has been somewhat defiant about not yielding even slightly to Democratic concerns about any of his appointments to the bench.

Because of the timing of the new vacancy, it seems improbable that the President would decide to put Judge Roberts forth as a candidate for the Chief Justiceship. That would short-circuit the existing process to put Roberts on the Court and, because it would require a new appointment, would further delay any addition to the Court’s membership. A new appointment would be necessary because Roberts was explicitly nominated to be an Associate Justice; that is how his name was sent to the Senate on July 29. (Rick Hasen at Election Law blog has an interesting post suggesting that the President may, indeed, want to resubmit Roberts’ nomination for the vacancy in the Chief Justiceship. Professor Hasen argues persuasively that the Court could function better with a vacancy in an Associate Justice’s seat than without a Chief Justice.)

There will be a great deal of speculation, in coming days, that the President would again think seriously about nominating his close confidant — Attorney General Alberto Gonzales — to the Court. The President may well turn his attention back to some others who have been on the White House “short list” for the Court, including Circuit Judges J. Harvie Wilkinson, Michael Luttig, and Michael McConnell.