If you’ve ever found yourself in a debate with a room full of brilliant people at the end of which not a single mind is changed, you know what it’s like to be a Supreme Court Justice on the losing end of an 8-1 decision. Nobody thinks you have the better end of the argument and your opinion tends to be less interesting for what it says about the matter at hand than for what it seems to say about you.

That’s why 10 Supreme Court decisions from last term, all of them decided 8-1, deserve a little more scrutiny. When a justice writes a lone dissent, she opens a window into her jurisprudence. Look closely, and you can see what worries her most. Last term, only one such dissent received widespread attention, when Justice Samuel Alito broke from the majority in Snyder v. Phelps. Alito sided with Albert Snyder, the father of a fallen soldier who sued the Westboro Baptist Church for picketing his son’s funeral. Snyder had all the makings of a blockbuster case: two compelling parties, a pressing issue, and a result that made all but the most devoted free speech purists a little queasy. Another case from last term, U.S v. Jicarilla Apache Nation didn’t have any of the same advantages. A dispute involving attorney-client privilege and a mismanaged trust, Jicarilla combined the gray tedium of case law with the byzantine complexity of the Bar exam. When the decision was handed down in June, even in legal circles, it barely made a ripple. 

It should have. For Jicarilla, like Snyder boasted a powerful solo dissent—this time from Justice Sonia Sotomayor—the first and only one she has authored in two years on the Court. 

As Supreme Court cases go, Jicarilla is a legal variant of the classic “duck test.” If the government acts like a trustee and calls itself a trustee, should it be treated like a trustee when a disgruntled beneficiary drags it into court? The Jicarilla Apache Nation thought so. In 2002, the tribe sued the federal government for $300 million for mismanaging its trust fund. The lawsuit remains unresolved. What the Court took up is whether the government is obliged to turn over all the legal documents related to its management of the trust. The overwhelming majority of the contested documents were handed over long ago, but the Tribe was seeking 155 more. It may seem strange to hold up such a large lawsuit over a handful of documents, but ask yourself why the government might be inclined to withhold them, and you’ll know why the tribe pursued the case all the way to the Supreme Court.

The government claimed these documents constituted legal advice protected by attorney-client privilege (the government being both the attorney and the client in this case). The reason for the privilege is simple: If lawyers thought their advice could become part of the public record, they would give their clients less of it. But trust law is a little different. Because a trustee must represent the interests of the trust’s beneficiaries, the courts have held that the beneficiaries are the real clients and entitled to review any legal advice the trustee has received.

In Jicarilla, the lower courts ruled that the role the government played was close enough to that of a private trustee that it could be forced to hand over all legal documents. The government appealed, arguing that, even while it is performing its trustee responsibilities, it is also acting in a separate capacity as the sovereign. In other words, it has two separate interests: those of the government and those of the tribe. As such, the trust law exception to attorney-client privilege should not apply, and the government should not be obliged to hand over every document related to its management of the trust.   

This was enough for Justice Ruth Bader Ginsburg, who penned a narrow concurrence that Justice Steven Breyer joined. But in a majority opinion that all five conservative justices signed onto (Elena Kagan recused herself) the court used Jicarilla as an opportunity to take aim at the idea the federal government should ever be held to obligations not expressly authorized in legislation.

The law of trusts is largely a creation of the common law, an accumulation of judicial decisions that fill in the gray areas of statutory law. Common law is the very definition of “judge-made law,” and so conservative jurists tend to look askance at it and reject outright the idea that the federal government should ever be confined by what Justice Clarence Thomas has referred to as the “murky principles of the common-law of trusts.” These words come from a dissent Thomas wrote in a 2003 case, United States v. White Mountain Apache Tribe, where the majority ruled the government could be held to common law obligations to restore trust property. With Sandra Day O’Connor replaced by John Roberts the outcome in Jicarilla was a different one and in his majority opinion, Justice Samuel Alito made clear what was at stake: “We will apply common-law trust principles where Congress has indicated it is appropriate to do so.” 

The most important word in that sentence is unspoken: it’s “only.” And the enormity of that new rule was not lost on Sotomayor. “We have never held that all of the government’s trust responsibilities to Indians must be set forth expressly in a specific statute or regulation,” she observed in her dissent. She went on to add: “The upshot of that decision, I fear, may very well be to reinvigorate the position of the dissenting justices in White Mountain Apache and Mitchell II, who rejected the use of common-law principles to inform the scope of the government’s fiduciary obligations to Indian tribes.” 

Sotomayor focused her dissent on the uncomfortable public policy implication of the majority opinion, namely, that the government could have legitimate reasons for managing the trust beyond, or perhaps even contrary to, the interests of the tribe without the obligation to turn over the evidence that proves it.  But the majority didn’t flinch. “Congress has structured the trust relationship to reflect its considered judgment about how the Indians ought to be government,” Alito affirmed, “[I]t has been altered and administered as an instrument of federal policy.”

Forget ducks. For Sotomayor, this doesn’t even pass the smell test. The government acts as a trustee and calls itself a trustee, but it won’t abide by any of the traditional duties that go with being a trustee unless it affirmatively accepts them. In effect, the government is using the word trust without feeling obliged by its definition. “There’s no need to use the word,” Sotomayor tartly noted in oral arguments, “because it wouldn’t be a trust.”

The problem for Sotomayor is that the government can be a trustee, but it can’t only be a trustee, and the dual nature of its relationship undermines the trust law exception to attorney-client privilege. Her response is to say that the interests of the trustee and beneficiary should always be aligned; that justice cannot tolerate the casual discharge of a sacred trust, particularly one owed by the federal government to a vulnerable group of people. “Given the history of governmental mismanagement of Indian trust funds,” she says in her dissent, the “application of the fiduciary exception is, if anything, even more important in this context than in the private trustee context.” Maybe so, but that is a moral reply to a legal conundrum. As a matter of law, Sotomayor would have been better off joining Ginsburg’s concurrence, which tried to provide a single exception to the traditional trust relationship. That she did not says a lot about the jurisprudential prerogatives of one of the newest members of the Court.

Jurisprudential prerogatives, and the moral imperatives that underpin them, are the stuff of lonely dissents, which tend to be less about the law than its shortcomings. They are written accounts of a judge’s reckoning with the oldest dilemma of her profession: that what is legal is not necessarily just, and what is just is not necessarily legal. As Sotomayor attests, they can be telling in their despair.