I asked about the new chief justice, and Stevens compared him with his predecessor, William H. Rehnquist. He praised Roberts as “obviously very, very smart, a very, very nice guy; he’s got a wonderful sense of humor.” He continued, “He does a fine job of running the conference, as Bill Rehnquist did, although I’m not sure I’m going to agree with him any more than I agreed with Bill Rehnquist.” I asked whether Roberts would succeed in his stated goal of persuading his colleagues to issue narrow, unanimous opinions. “I don’t think so,” Stevens replied. “I just think it takes nine people to do that.” He noted that Roberts had “a bit of a honeymoon period” during his first term. “I think maybe the first few months we all leaned over backward to try to avoid writing separately in a couple of opinions,” he said, “but I don’t think that will last.”

In general, Stevens said, the idea that a justice can sway his colleagues through collegiality and personal lobbying — a talent often attributed to Justice William J. Brennan Jr. — is exaggerated. He suggested that in most cases, justices cannot be swayed to change their votes once they make up their minds, and when they can be swayed, it is only as a result of legal arguments, not charm or charisma. “I was very fond of Bill Brennan — loved the guy and had great admiration for him,” Stevens said. “But it’s simply not right to say that he was able to craft the majority. He just had five votes on his side!”

Stevens himself, however, has been notably successful in building majorities by courting his fellow justices — in particular, Kennedy. His methods of persuasion are intellectual rather than personal, and they are closely tied to the court’s procedure for deciding cases. After the justices hear the oral arguments, they meet in a private conference to deliberate. After the chief justice speaks, each of the remaining justices speaks in order of seniority, so that Stevens speaks second. Then the justices vote, and the majority opinion is assigned. The majority opinion later circulates among the justices, and on rare occasions a justice may then change his or her vote, and a majority can become a dissent. But “you very rarely win votes if there aren’t five votes persuaded after our conference,” Stevens stressed. “Very rare.”

When he is in the majority, Stevens is careful not to lose votes that start off on his side, often assigning the opinion to Kennedy when Kennedy seems to be on the fence. “Sometimes,” he told me, “in all candor, if you think somebody might not be solid” after casting a vote in conference, “it might be wiser to let that person write the opinion,” because after defending a position at length, people “tend to become even more convinced” than when they started. For example, Stevens was effective in winning over Kennedy by asking him to write the majority opinion in Lawrence v. Texas, the 2003 decision striking down sodomy laws, which many liberals consider the Brown v. Board of Education of the gay rights movement. “It worked out O.K.,” Stevens told me, with typical understatement. “I don’t know if I’m entitled to the credit or Tony’s entitled to the credit, because he wrote an exceptional opinion.” In other cases, Stevens has written the majority opinion himself in an effort to shore up Kennedy’s vote. In April, for example, in a 5-to-4 case, the court allowed a lawsuit to proceed against the Environmental Protection Agency for its refusal to regulate global warming under the Clean Air Act; by citing several of Kennedy’s previous opinions in his own opinion, Stevens persuaded Kennedy to stay in the liberal camp.

On the issue of abortion, however, Stevens has failed to persuade Kennedy to vote consistently with the liberals. I asked Stevens about the decision last term in which Kennedy, writing for the five more conservative justices, upheld the federal ban on partial-birth abortion. Stevens said that the federal ban was deeply flawed and that Kennedy’s rhetoric about the need to protect women from the emotional trauma of abortions was frustrating. But he noted that the real-world effect of the defeat was minimal because of the widespread availability of alternative abortion procedures. “The statute is a silly statute,” he said. “It’s a silly statute.” He added, “It’s just a distressing exhibition by Congress, but what we decided isn’t all that important.”

I asked whether Stevens thought the right to abortion recognized in Roe v. Wade would survive in his lifetime. “Well, it’s up to Justice Kennedy,” he replied. “I don’t know about the two new justices” — Roberts and Alito — “but I kind of assume it may well be up to him.” Abortion rights supporters may take solace in the fact that Stevens indicated that Kennedy seemed to view the regulation of so-called partial-birth abortions as consistent with Planned Parenthood v. Casey, which upheld the central holding of Roe v. Wade. “I don’t think he thinks this” — the recent abortion opinion — “requires him to change his views at all,” Stevens said. “We’ll have to wait and see. I suppose there are a lot of people out there praying I get out of the way.”

Stevens was born on April 20, 1920, the youngest of four boys. His paternal grandfather, James W. Stevens, made a fortune as the founder of the Illinois Life Insurance company, and in 1927, his father, Ernest J. Stevens, built the Stevens Hotel in Chicago, now the Hilton Chicago, which he called “the largest and finest hotel in the world.” Built for a staggering price of $30 million, the Stevens hotel included 3,000 guest rooms, a movie theater and an ice cream factory. As Charles Lane reported in a Washington Post article in 2005 about Stevens’s childhood, young Stevens and his brothers posed as models for the bronze sculptures by the grand stairway.