Thanks to the Constitution’s federalist structure, America has fifty administrative states in addition to the federal leviathan.

Sometimes, state and federal governments jointly administer “cooperative federalism” programs established by Congress and state legislatures, such as the Clean Air Act or Medicaid. More often, state regulatory agencies implement local regulations, independent of the federal government. Here, the quintessential example is zoning.

These programs, in turn, engender controversies that go before state courts. Thus, administrative law develops independently in each state.

Take Chevron deference, the most famous principle in (federal) administrative law. Under the Chevron doctrine, Article III courts yield to an agency’s interpretation of the law—including the scope of the agency’s own authority—even if the court thinks that it has a better reading of the statute.

At the state level, however, only a subset of courts has adopted a Chevron-like approach to statutory interpretation.

In a landmark 2008 article, Michael Pappas surveyed state courts to discern how they interpret laws that empower regulatory agencies. Many such courts review statutes as a blank slate, without any deference to government agencies. Others were deferential. A couple courts operate anti-deference doctrines; that is, they expressly discourage reliance on an agency’s interpretation of the law. In short, there is a great deal of variety in approaches.

Of course, legal doctrine is fluid. It’s always changing. Which brings me to what’s going on in Mississippi.

In 2008, when Pappas performed his survey, he described Mississippi courts as affording “strong deference” to a state agency’s statutory interpretation—stronger than even Chevron.

But the state’s supreme court pivoted 180 degrees a decade later in King v. Mississippi Military Department. In that case, the court unanimously ended the practice of giving deference to state executive agencies’ interpretations of statutes.

Now, the court seems to have its eyes set on another major deference doctrine. Up to this point, I’ve been discussing statutory interpretations. Yet agencies also interpret their regulations, which have the force and effect of law (just like a statute).

Judicial deference to an agency’s regulatory interpretations is even more controversial than statutory deference. With either doctrine, courts arguably abdicate their duty to “say what the law is.” But regulatory deference further offends our constitutional structure by allowing the rule-writer to serve as the rule-interpreter.

While the Mississippi Supreme Court gives this kind of deference–for now–change is on the horizon.

Last week, in Central Mississippi Medical Center v. Mississippi Division of Medicaid, three judges on the court announced that the “practice of the courts deferring to an executive-branch interpretation of agency regulations should end.”

Though the three judges were in the minority, the politics of the decision indicates that their argument enjoys momentum. As a general matter, progressives support deference, while conservatives oppose these sorts of doctrines. In this context, it is noteworthy that two of the court’s most liberal justices (Kitchens and King) were among the avowed opponents of regulatory deference. This strongly suggests that the doctrine’s days are numbered in Mississippi.

Were the Mississippi Supreme Court to jettison judicial deference to an agency’s regulatory interpretation, the justices would be following in the footsteps of the nation’s high court. Last summer, the Supreme Court gutted the doctrine at the federal level.