This much is known for sure: His favorite movie is "Doctor Zhivago."
After that, surprisingly little is known about John Roberts, who is about to take up the reins of one of the most powerful institutions in American government as the 17th chief justice of the United States.
Will he vote to overturn the abortion precedent Roe v. Wade? Some legal analysts say yes, others no.
Will he favor states' power over Congress's efforts to pass federal laws under the Commerce Clause?
Does he have a long-term strategy to move the court to the right, or will he gravitate to the center on some issues, as Justice Sandra Day O'Connor did?
In many ways the nation has a less clear impression of Judge Roberts now than before his confirmation hearings. But according to Roberts's philosophy of judicial modesty and restraint, that's a good thing. While American democracy thrives on knowing in advance the policy choices of presidents and senators, judges perform a different role, Roberts says. With them, less is more.
"We don't know precisely how he will rule in Roe v. Wade and other specific issues, but I don't think that is necessarily such a bad thing," says John Maltese, a political science professor at the University of Georgia and author of "The Selling of Supreme Court Nominees."
"People should take some comfort in the fact that he is not predetermining how he will vote on certain issues, if he is really being honest about this," Professor Maltese says. "Judges are, after all, supposed to be deciding the cases that come before them, and we expect that they should not have predetermined notions about how cases should be decided."
Thursday, the Senate confirmed Roberts by a vote of 78 to 22.
As chief justice, Roberts will occupy the center chair at the Supreme Court and become "first among equals." Although he casts only a single vote like each of the other eight justices, as chief he wields the power when in the majority to assign who will write the majority opinion. He will preside over oral arguments and the closed-door conferences in which the justices discuss which cases to take up and how to decide pending cases. As the second-youngest chief justice, he could have an impact for decades to come.
Roberts will also serve as the chief administrator of the entire federal judiciary and run the operations of the Supreme Court building. He would preside over any presidential impeachments. And he makes appointments to the Foreign Intelligence Surveillance Court, which approves espionage wiretaps aimed at uncovering spies and terrorists.
But Roberts's most significant contribution as chief justice will be how effectively he interacts with his fellow justices in reaching consensus on particular cases, constitutional scholars say.
Prior to Chief Justice William Rehnquist's death earlier this month, the same lineup of justices had sat together for 11 years, the longest period of stability on the high court since the 1820s. Now with Roberts joining the court and the prospect of a replacement soon for retiring Justice O'Connor, court watchers say an entirely different dynamic may emerge as the justices establish new working relationships.
"As chief there's every reason to think that he will be an efficient taskmaster, like Rehnquist, and that he has the talent to facilitate collegiality on the court," says Howard Gillman, professor of political science, history, and law at the University of Southern California. "More importantly for conservatives, he has as good an intellect as [Justice Antonin] Scalia without his tendency to alienate his colleagues. And that might put him in a better position to forge a more reliable conservative majority on the court."
Legal analysts will be watching closely to see if Roberts changes the inner workings of the court by, perhaps, beefing up the system of reviewing incoming appeals, broadening the kinds of cases being heard, and increasing the number of cases the court decides each term. Twenty years ago the court took up as many as 150 cases per term. In the final years of the Rehnquist Court that number had dropped to about 80.
Roberts's arrival at the high court may prove historic for another reason. Rising to chief justice at the relatively tender age of 50, he could occupy the Supreme Court's center chair for 30 years or more. That would place him in the company of a legal giant, John Marshall, who served as chief for 34 years in the high court's formative period in the early 1800s.
While Roberts declined during his confirmation hearing to offer forecasts of how he might vote in particular cases, he did reveal some new information. He announced that he objects to American judges relying on foreign law as precedent in American courts. This places him on the conservative side of an ongoing debate among the justices. Roberts says such reliance on foreign precedent would undermine the legitimacy of the courts and allow US judges to vastly increase their discretion to engage in results-oriented judging.
"If a court relies on a decision of a foreign judge ... no president accountable to the people appointed that judge, no Senate accountable to the people confirmed that judge, and yet that judge is playing a role in shaping a law that binds the people of this country," he wrote in response to Sen. Edward Kennedy (D) of Massachusetts.
On Second Amendment gun rights, a potentially explosive issue, Roberts predicted that because of a sharp split among the appeals courts "it is likely that this question will reach the Supreme Court soon." The comment is significant because the high court has avoided taking up the gun-rights issue since the 1930s, but Roberts appears ready to confront it.
Another potential hot-button issue is court-stripping. During his confirmation hearing, Roberts backed away from an earlier position he took as a young lawyer in the Reagan administration supporting a theory that the Constitution permits Congress to strip the federal courts of jurisdiction in controversial cases. Roberts now says that any effort to limit the jurisdiction of the courts would raise "very grave constitutional issues."
Another Roberts revelation during the hearing was his frequently repeated recognition of a privacy right contained within the due process clause of the Fifth and Fourteenth Amendments. While some observers might take the admission as code that he would uphold abortion and gay-rights rulings, legal analysts say Roberts has not provided enough information to forecast how these views might translate in a specific decision.
"Overturning Roe tomorrow would be completely consistent," says Michael Carvin, a Supreme Court advocate who served in the Reagan Justice Department at the same time as Roberts. But he adds that it is unclear if Roberts will vote that way.
Mr. Carvin says the key to understanding Roberts is to focus on his approach to the rule of law and judicial modesty. "With people like Roberts, their personal leanings and views on policy issues are irrelevant," he says. "If they are bright and they follow the rule of law, they are going to come to conclusions that commentators are going to characterize as conservative in the vast majority of cases."
Professor Gillman has a different perspective. "In the modern history of the Supreme Court ideological labels always apply. They make the justices uncomfortable but it is incontrovertible that the justices are heavily influenced by their political ideology," he says.
"Roberts's votes on the court will reflect his lifelong commitment to the promotion of conservative values and principles," Gillman says. "That's why Bush picked him."
With the court's 2005-2006 term set to begin next Monday, legal scholars are awaiting the first Roberts opinions - perhaps as early as November. Until then many analysts on both the left and the right are nervously contemplating the enormous impact this self-described humble umpire will have on the future course of American history.