It is difficult to know how much, or even whether, such personal interactions influence Justice Kennedy’s jurisprudence. As Mr. Cappuccio, now general counsel of Time Warner Inc., said: “He takes liberty very seriously. Sure, I think it could be natural that one’s life experiences can have an impact. But I think it would be belittling of Justice Kennedy to say he might vote to recognize a constitutional right to same-sex marriage just because he knows people who are gay.”

Still, here in the California capital, where Justice Kennedy grew up and spent most of his time before joining the Supreme Court in 1988, some see the long arc of his past playing a role — both in his decades-long friendship with Mr. Schaber and in the threads of moderation and tolerance woven into his Sacramento roots.

In Warren’s Shadow

This California city during Anthony Kennedy’s childhood in the 1940s and ’50s was not, those who lived here say, an especially partisan or judgmental place. It was dominated by a looming figure: Earl Warren, the Republican governor of California and future chief justice of the United States.

“Sacramento was extremely tolerant,” said Earl Warren Jr., 85, a son of the governor and a retired lawyer. “We had lots of gay people who were very prominent. If you knew or suspected that was the case, it didn’t make any difference. I was a Boy Scout in Sacramento in the 1940s, and we had gay leaders in the community who were also gay scout leaders. They were good friends and good leaders, and there was never any problem.”

In 1941, when Anthony Kennedy was 5, his family settled in Land Park, a neighborhood of curving streets, stately homes and lawns dotted with rhododendrons — a place, said Joe Genshlea, a lifelong friend, “where everybody knew everybody else, and life was just very stable.”

The writer Joan Didion, a good friend of the future justice’s older sister, was a frequent guest in the Kennedy home. The boxer Max Baer — whose son Max Jr. went on to play Jethro on “The Beverly Hillbillies” — lived a few blocks away. The Warren children, who attended the same public high school as the future justice, were often around.