The greatest restraint on judges is that they are bound by a written text — or, at least, that they are supposed to be.

Members of Congress gain their legitimacy from the will of the people, so they have broad ranging authority to enact laws that, in their opinion, will serve those people. Judges, by contrast, have no democratic legitimacy and far less discretion. Their sole task, at least in theory, is to apply written law to individual cases.

Which is why Justice Clarence Thomas’ opinion for the Supreme Court in Franchise Tax Board v. Hyatt is troubling. Hyatt does not simply overrule a longstanding precedent, it does so while admitting that nothing in the text of the Constitution supports such an outcome. Loyalty to constitutional text and loyalty to written precedents are the twin pillars that stabilize our system of law. The Supreme Court just abandoned both of them.

The rule Thomas announces in Hyatt, by his own admission, is “not spelled out in the Constitution.” It’s also not spelled out in the Supreme Court’s precedents. Much to the contrary, Hyatt explicitly overrules a 40-year-old decision. The decision was 5-4, along familiar partisan lines.

The specific legal question at issue in Hyatt isn’t especially exciting — “whether the Constitution permits a State to be sued by a private party without its consent in the courts of a different State.” Before Monday’s decision in Hyatt, the answer to this question was “yes.” Now, it is “no.”

But the implications of Hyatt stretch far beyond the case’s direct holding.

Who needs the Constitution when you have five votes?

Thomas often claims that the only legitimate way to read the Constitution is to examine its text, and determine what its specific words would have meant at the time of their framing. He routinely lectures his colleagues that their opinions should be “more faithful to the original understanding” of our founding document.

This insistence that “originalism” is the only legitimate method of constitutional interpretation isn’t just some rhetorical tactic unique to Thomas. It’s practically a matter of conservative identity. Leaders of the Federalist Society, the organization that President Donald Trump relies upon to select judicial nominees, routinely congratulate themselves for the rise of conservative originalism.

And yet, in Hyatt, we have Thomas embracing a doctrine that can be found nowhere in the Constitution’s text.

In fairness to Thomas and his four conservative colleagues, the doctrine at issue in Hyatt is not entirely ungrounded — even if it cannot be found within the Constitution itself. It derives from a broader doctrine known as “sovereign immunity,” which often forbids state governments from being hauled into court without their consent.

Sovereign immunity is mentioned in the Constitution in a very limited context. The Eleventh Amendment forbids federal courts from hearing suits “commenced or prosecuted against one of the United States by citizens of another state, or by citizens or subjects of any foreign state.” Thus, a citizen of one state typically may not sue a different state in federal court (although the courts have also developed several workarounds which permit state officials to be sued if they violate the Constitution).

But Hyatt involves a lawsuit in state court, not federal court. The Eleventh Amendment simply has nothing to say about this question.

Several past Supreme Court decisions rely on an historical narrative that the courts used to extend sovereign immunity beyond the Constitution’s text. As the court held in Alden v. Maine, “the States’ immunity from suit is a fundamental aspect of the sovereignty which the States enjoyed before the ratification of the Constitution.” Thus, the Supreme Court argued, states should be assumed to retain this immunity unless the Constitution specifically strips it from them.

Alden‘s abandonment of constitutional text is no less suspicious than the decision in Hyatt. Nonetheless, decisions like Alden do have one thing going for them — they are precedents of the Supreme Court that are entitled to deference by future justices. Hyatt, however, does not have this advantage. Hyatt overrules the Supreme Court’s 40-year-old decision in Nevada v. Hall.

As Justice Stephen Breyer explains in his dissent, Hall rested on a very different historical narrative than the one that drove decisions like Alden.

Prior to the Constitution’s ratification, the former British colonies were each independent nations. “At the time of the founding,” Breyer writes, “nations granted other nations sovereign immunity in their courts not as a matter of legal obligation but as a matter of choice, i.e., of comity or grace or consent.”

The Constitution stripped the states of their status as independent nations and bound them into a union led by a federal government. Yet the Tenth Amendment provides that any “powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.” Thus, Breyer writes, “compelling States to grant immunity to their sister States would risk interfering with sovereign rights that the Tenth Amendment leaves to the States.”

Unlike Thomas, Breyer is able to point to actual words in the actual Constitution which support his argument that citizens of one state should be allowed to sue that state in another state’s courts. And, unlike Thomas, Breyer had precedent on his side.

Winter is coming

The doctrine that courts should be highly reluctant to abandon past precedents is known as stare decisis. Thomas is not a fan. As the late Justice Antonin Scalia once quipped, Thomas “does not believe in stare decisis, period.” The Supreme Court’s longest-serving justice does not feel bound by past precedent.

Yet, as his Hyatt opinion makes clear, he also does not feel bound by constitutional text.

Thomas’ greatest con is convincing so much of the nation’s legal community that he is an originalist — a man who supposedly grounds his interpretation of the law in the way the words of our Constitution were originally understood. But Hyatt relies on a historical narrative divorced entirely from those words. Again, only Justice Breyer offered a textualist argument in his dissenting opinion.

Breyer concludes his dissent with a warning — “today’s decision can only cause one to wonder which cases the Court will overrule next.” Not long after Thomas handed down his opinion, the New Yorker’s Jeffrey Toobin offered a translation of Breyer’s warning on Twitter: “Roe v. Wade is doomed.”

But the reality is likely to be even more destabilizing than Toobin suggests. Thomas is a hardline conservative — so much of a hardliner that he’s suggested that federal child labor laws are unconstitutional. He is also a man unbound by either text or Supreme Court precedent.

And he just convinced four of his colleagues to join him for the ride.