To me, she was always Mrs. O’Connor, the mom next door. Yet she was always—even then, in the mid-1960s in the suburbs of Phoenix, Arizona—the person who would be Justice O’Connor. Long before her breakthrough appointment to the U.S. Supreme Court made her one of America’s most renowned jurists, Sandra Day O’Connor showed the qualities of pragmatism, wisdom, and patience with human frailty that marked her time on the Court—and make her legacy more precious than ever today.

When I was 6, my family moved into a brand-new house in Phoenix. Before the construction was finished, I encountered a boy my age playing amid the studs, wires, and boxes of nails. (Boys could do such things back then.) One of the three O’Connor boys, he turned out to be a neighbor. Because we went to school together down the street, I found myself often going in and out of the O’Connors’ house, a low-slung desert rambler, built distinctively with adobe bricks. I still recall the pitch and inflection of Mrs. O’Connor’s greeting: “Well, hello, Jon Rauch!”

Mrs. O’Connor did not put on airs. For me, the highlight of every year was Halloween at the O’Connors’ place, which they converted into a multiroom haunted house. Cackling wickedly and stirring a bubbling cauldron of dry ice, Mrs. O’Connor dressed up as a black-caped, pointy-hatted witch, while her husband, John, lumbered around with a monster mask on his face and a plastic knife through his neck.

Yet I soon became aware that the mom next door was a formidable personage. She seemed to be involved in every kind of community activity. My father, himself a lawyer, told me that Mrs. O’Connor was a hard-driving, brilliant, and omnisciently prepared attorney. He related how, when she was an assistant state attorney general and he was representing a welfare claimant, he’d experienced every litigator’s worst nightmare: In open court, she’d uncorked an authoritative statute he had never heard of. (He lost.) No one was surprised when she was appointed to the state Senate and rose to be its first—and the nation’s first—female majority leader. Following that, she was appointed a judge on Arizona’s Court of Appeals.

Phoenix in the ’60s and ’70s was a conservative, solidly Republican state—home to Barry Goldwater, the fiercely anti-communist, anti-union U.S. senator and 1964 Republican presidential candidate. (His hilltop house was within sight of my neighborhood.) For the most part, though, Arizona’s brand of Republican was buttoned-down and businesslike. William Rehnquist, the future U.S. chief justice and another Phoenix Republican fixture in those days, was considered far-right. Sandra Day O’Connor embodied the party’s center: conservative but pragmatic, oriented toward solving problems rather than creating or amplifying them.

The same no-nonsense, get-it-done attitude that made her a person who befitted any boardroom or community group made her the kind of legislator and judge around whom people gathered and for whom things happened. You knew you could rely on Mrs. O’Connor to be the grown-up in the room.

That persona traveled with her to the country’s highest court. In 1981, when Potter Stewart’s seat opened and President Ronald Reagan pledged to fill it with a woman, I told friends that I knew the perfect person—but that the president would never pick her, because she was too little known and insufficiently ideological for the party’s already fiercely conservative right. But Goldwater, of all people, went to bat for her. So began a Supreme Court career that, to this day, remains underappreciated.

Justice O’Connor’s jurisprudence flummoxed and annoyed legal scholars. She had no overarching judicial philosophy, unlike conservatives such as the combative originalist Antonin Scalia, the purist libertarian Clarence Thomas, or the committed textualist Neil Gorsuch. Her opinions could be murky and temporizing. She was conservative, no doubt about that, but she was also a justice who had previously been a working politician, and it showed in her holdings: She looked for solutions and, more important, for ways to ensure that regular people could look for solutions. She understood the Court’s role as political—not in the activist sense of legislating from the bench, but in the realist sense of seeing the Court as embedded in a political matrix where rigid doctrine could do more harm than good. Known for years as the Court’s swing vote—for a while, some called it the O’Connor Court—she was also, on many occasions, its anchor to reality.

It was like her to rule, in Grutter v. Bollinger, that affirmative action could continue in university admissions—but only for a while, not forever. It was like her, in Planned Parenthood v. Casey, to trim but not eliminate the constitutional right to an abortion. Her difference-splitting holdings infuriated constitutional purists on both sides, but she followed a higher kind of constitutionalism: a recognition that not every issue is ripe to be decided judicially.

Sometimes, like the mom she was, she needed to tell the kids to go back and try harder. Ambiguity and compromise, she saw, could be vital aspects of Supreme Court jurisprudence. If academics and ideologues disapproved, so much the worse for them.

That the lack of an O’Connor on today’s Supreme Court has become a costly deficit goes almost without saying. The Court is often criticized for being too political, but Justice O’Connor’s virtue was that, having been a politician, she had an innate feel for consensus and consent. Today, all nine justices were appointed from U.S. appellate courts or legal academia. None has run for or held elective office. The result has been the kind of sweeping, ideologically inflected jurisprudence that Justice O’Connor avoided. She is rightly remembered as the Court’s first woman; she should also be remembered, alas, as its last politician.

In adulthood, I mostly lost touch with Mrs. O’Connor. Still, with time, I only grew in my appreciation of her qualities. They have become lamentably scarce in American public life and especially in the Republican Party, which owed her so much and yet became so hostile to her legacy. After she retired from the Court, I was surprised when she took up the cause of civics education. Wasn’t this too marginal and small-bore a cause for a person of her stature? Now I understand that, as usual, she was practical and prescient.

Back in August 1981, when she was in Phoenix awaiting confirmation, I made the familiar backyard trek for a hello visit. Despite her sudden elevation to global fame, there she was, the same Mrs. O’Connor, breading fish filets in the kitchen.

Twenty-four years later, in 2005, she received my father and me in her Supreme Court chambers. At that point, she had submitted her resignation from the Court, but the recent death of Chief Justice William Rehnquist delayed her departure (which would not occur until the following year). She expressed frustration, because her husband’s increasing dementia needed her full attention. She was still the problem-solver, the responsibility-taker, the adult in the room—and she was needed elsewhere.

More than ever, her spirit is needed here, today.