When Sandra was just 16, she went off to college (and then law school) at Stanford, and it was from her time there that Thomas lands his biggest scoop. World War II had just ended, and the campus was packed with vets, several of whom, it appears, took a shine to Sandra Day. She received four marriage proposals at Stanford, and one, amazingly enough, came from “a lanky Midwesterner with a flattop haircut named William Rehnquist.” The story of their courtship unfolds like a highbrow rom-com: They meet-cute sitting next to each other in class; he takes her on “idyllic” (his word) picnics by the beach; she invites him home, but he fails the audition at the Lazy B when he flinches at her father’s offer of a bull’s testicle grilled on a branding fire. A rival, John O’Connor, appears on the scene; but Bill, still smitten while clerking on the Supreme Court, writes to her, in lawyerly style, “To be specific, Sandy, will you marry me this summer?”

Sandy strings Bill along for a while but ultimately marries John instead. The O’Connors’ marriage is at the heart of this biography, and it’s nothing less than a great love story. She and John settle in Phoenix (as do Rehnquist and his wife), and the future justice does volunteer work until she lands a job as an assistant attorney general. (Immediately out of law school, she was offered positions only as a legal secretary.) Her professional ascent is rapid. She wins a seat in the Arizona State Senate, tames that boys’ club enough to become majority leader and then moves to a judgeship on the state appeals court. Her life with John is a study — in that maddening phrase — in having it all. They hiked, skied and golfed; networked with big shots like Chief Justice Warren Burger; and raised three rambunctious boys (one of whom went on to climb Mount Everest). In her spare time, she cooked every recipe in Julia Child’s “Mastering the Art of French Cooking.” “Oh, for God’s sake, Sandra,” a friend lamented about that particular feat, “do you always have to overachieve?”

In the 1980 campaign, Ronald Reagan had promised to appoint the first woman to the Supreme Court and, thanks in part to a good word from Burger, nominated O’Connor the following year. Those were more innocent, or at least less partisan, days when it came to the politics of the justices, and it was good enough for Reagan that O’Connor was a loyal Republican. There was no heavy-duty scrutiny of her views either from the White House or the Senate; indeed, at that early stage, she hadn’t really thought much about the issues that come before the Supreme Court.