In recent months, the Supreme Court has stepped into one controversy after another—taking a case that threatens affirmative-action programs, creating a road map for states looking to copy Texas’s S.B. 8 and nullify constitutional rights, and using the shadow docket to signal major changes to abortion and voting-rights laws. In a matter of months, the Court seems poised to both dramatically expand gun rights and overrule Roe v. Wade. Polling demonstrates that the Court’s popularity has fallen to an all-time low, driven by perceptions that the justices are partisan. The Court’s conservative majority seems remarkably unconcerned about potential damage to its reputation. That may come as no surprise: Supreme Court justices have lifetime tenure unless they are impeached.

What’s to stop a runaway Court? Not impeachment—only one justice has ever been impeached, in 1805, and he was ultimately acquitted. Not long ago, political scientists, historians, and legal scholars argued that the Court would self-moderate to preserve its so-called legitimacy. And that seems to have been right—at least then. In those times, the Court’s decisions generally reflected popular opinion on major issues of the day. And for good reason: Historically, when the Court ignored a national consensus—and seemed indifferent to arguments about legitimacy—the consequences were serious. Congress stripped the Court of jurisdiction and manipulated its size. States defied the Court, and individuals ignored it. Paying attention to concerns about legitimacy, by contrast, has generally allowed the Court to preserve its authority. Since Franklin D. Roosevelt’s plan to pack the Court failed in 1937, resistance to the Court has been more subtle, and the justices have generally tried to avoid decisions that set off a major backlash. At least until recently.

All of this makes it important to understand what we mean when we talk about the legitimacy of the Supreme Court. As the Harvard Law professor Richard Fallon has shown, defining legitimacy takes some work. It can refer to the Court’s moral standing—a concern most acutely raised in legal systems, such as those of Nazi Germany, that sanction obvious human-rights violations. Legitimacy, too, can refer to the perceptions of the legal community—do lawyers, judges, and academics believe that the justices are using reasonable interpretive methods and applying them in good faith? Most often, legitimacy describes the Court’s ability to command the public’s respect and obedience. Whichever definition you use, none seems to have much of a moderating influence on the Court’s conservative majority today.

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Part of this is that the legal community has changed since 1992. Then, the Federalist Society, only a decade old at the time, was on its way to creating a conservative legal network with a farm team of prospective judicial nominees, a foothold in elite institutions, and an arsenal of effective legal arguments. Today, the Federalist Society is a giant—responsible for reshaping the Supreme Court—with tens of thousands of members, a large budget, and impressive political connections. If the Court reverses Roe, holds affirmative action to be unconstitutional, dramatically expands gun rights, and hamstrings the administrative state—and does so quickly—it will damage its own reputation with the broadly defined legal community. But the Republican Party and the Federalist Society have created a parallel community with its own norms and sources of validation. The justices may not worry about losing legitimacy in one elite legal circle when they will be heroes in another.