RUTHFULLY YOURS

In the constitutional challenge to the Affordable Care Act, Chief Justice John Roberts held that requiring citizens to buy health insurance was beyond the power of Congress to regulate interstate commerce. Yet he provided the fifth vote to uphold the law. How? Justice Roberts adopted what he called a “saving construction” that converted what the statute termed an “individual responsibility requirement” that was enforced by a “penalty” into an option either to buy health insurance or pay a small tax. Although he admitted that this wasn’t the most “natural” reading of the text, rewriting the law this way allowed him to defer to the will Congress.

This example illustrates how limited government has been undermined by creative doctrines employing the rhetoric of “judicial restraint” to obviate the Constitution’s text and facilitate unconstrained activism by legislatures. Proponents, such as Republican Judge J. Harvie Wilkinson of the Fourth Circuit, argue that unelected judges should defer to the “will of people” as reflected in legislation.

In practice, the claim that laws and administrative regulations reflect the will of the public is often a fiction. In the economic sphere, regulations are more commonly the product of pressure from politically connected and well-established companies at the expense of upstart entrepreneurs. Because voters know little about these laws and their impact, they can’t hold their representatives accountable for enacting them, and the few affected individuals can hardly influence a general election.

In “Terms of Engagement,” Clark Neily draws upon his extensive experience as a lawyer for the libertarian Institute for Justice to expose this pervasive legal maneuvering and identify the human costs of so-called judicial restraint. He describes laws requiring Americans to take hundreds of hours of training to become state-licensed cosmetologists before they can braid hair, “even when they provide no other services and use no scissors, chemicals, or potentially hazardous instruments.” Louisiana requires a florist license before a person can arrange flowers for pay; Louisiana and Tennessee require anyone who sells a casket to the public to be licensed as a funeral-home director.

Countless such restrictions on individual liberty are supposedly needed to protect the health and safety of the public. But as Mr. Neily explains, under the current doctrine favoring restraint, government lawyers needn’t provide any actual proof of a genuine health or safety problem, or show that the law’s restrictions address whatever problems may truly exist. Indeed, existing doctrine requires judges to make up reasons for such restrictions, no matter how disconnected these rationales may be from why the regulations were adopted.

Thus does constitutional law enshrine what economists call “rent seeking” by the politically powerful. The price is the economic liberty that once fueled the American dream.

Most outrageously, under the doctrines of deference and restraint, courts are supposed to defer to legislators’ own assessments of the constitutionality of their acts. Legislators then turn around and rely on the courts’ willingness to uphold their powers as proof of their constitutionality. So congressional supporters of ObamaCare claimed it was constitutional because the courts would uphold it; once enacted, supporters of the law urged the justices to defer to Congress’s judgment that the law was within its constitutional powers. Call this “double deference.” With judges deferring to legislatures and vice versa, no one actually enforces the Constitution’s constraints on legislative power.

The alternative to judicial conservatism’s deference to legislators is constitutional conservatism founded on deference to the Constitution itself. Mr. Neily identifies the three premises of constitutional conservatism: First, “the Constitution is a legitimate source of political authority,” he writes. By this he means that “the Constitution establishes a legal framework that determines what actions the government may properly take and what actions it may not. Government officials are bound to obey the Constitution, and they must conform their actions to the limits it provides.”

Second, he writes, “it is appropriate for judges to determine the unconstitutionality of government action.” This is not to advocate judicial supremacy. Like a regime of health and safety inspections, all three branches of government, including the judiciary, must inspect a law and concur before a measure can safely be imposed on the general public. Otherwise, legislators become the judges in their own case; and, in a contest with their masters, government “servants” get the last word on the scope of their own powers.

Finally, Mr. Neily says, “judges should base their rulings on the text of the Constitution instead of their own policy preferences.” The text includes enumerated rights like the freedom of speech and the enumerated-powers scheme in the text of Article I, as well as the more abstract protections of liberty enshrined in the text of the Ninth Amendment—”The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people”—and the Privileges or Immunities Clause of the 14th Amendment. All these and other power-constraining pieces of constitutional text had to be interpreted out of existence to allow judges to blindly defer to legislators who then turn around and defer to the courts.

Mr. Neily then explains in detail how real judging can work, while responding cogently to those who characterize such judicial engagement as “activism.” Simply put: Judges need to ask the government to explain why a restriction on liberty is both necessary and proper and then realistically examine the proffered explanation. This modest degree of judicial skepticism isn’t activism. It is the simple duty of those who don black robes and take an oath to uphold the Constitution on behalf of the people.

Mr. Neily’s book is a compelling examination of how we have taken so wrong a constitutional turn and how constitutional limits on government can effectively be restored.

Mr. Barnett is a constitutional-law professor at Georgetown University, where he directs the Georgetown Center for the Constitution. He is the author of “Restoring the Lost Constitution: The Presumption of Liberty.”