A week or so ago, the nomination of George Mason Law’s Neomi Rao to fill Justice Brett Kavanaugh’s seat on the D.C. Circuit ran into some unexpected headwinds when Missouri’s freshman Republican senator, 39-year-old Josh Hawley, raised several concerns about her views, all centered around his opposition to abortion. Fearing that the nomination might fail in committee, the Wall Street Journal’s editorial board took the extraordinary step last week of running not one but two house editorials questioning Senator Hawley’s “judgment.” In the end, the senator came around. On Thursday, Prof. Rao, since July 2017 the head of the Office of Information and Regulatory Affairs and a highly credentialed critic of the administrative state, was voted out of committee on a straight party-line vote of 12–10.

But questions linger about the motivation and thinking behind Sen. Hawley’s opposition, not least because he himself is highly credentialed (Stanford, Yale Law, clerk for Chief Justice Roberts), and he came of age when the issues he raised were being hotly debated on the Right. He was quoted initially, for example, as saying that “I am only going to support nominees who have a strong record on life”—the “litmus test” approach to nominations more often associated with the Left. But he was also cited as concerned, more broadly, that Rao “might be comfortable with substantive due process,” the doctrine the Supreme Court employed in 1973 when it found a right to abortion. It seems, however, that he may have finally reconsidered that larger concern, for the Journal’s second editorial tells us that “Mr. Hawley now claims he doesn’t object to using this method to incorporate the Bill of Rights to states, only to progressive abuses of substantive due process.”

Few constitutional doctrines have more vexed conservatives than substantive due process, so a word is in order on the subject, especially given that it’s likely to reemerge with future nominations. Justices Scalia and Thomas have called the doctrine an “oxymoron,” yet that hasn’t stopped the Court’s conservatives from employing it variously, as in finding that the Second Amendment binds the states pursuant to the Fourteenth Amendment’s instruction that no state shall “deprive any person of life, liberty, or property, without due process of law.” And a fortnight ago, joined this time by the Court’s liberals, they again invoked the Fourteenth Amendment’s Due Process Clause to apply the Eighth Amendment’s Excessive Fines Clause against the states, although here, as elsewhere, Justices Thomas and Gorsuch expressed their concerns that the Fourteenth Amendment’s Privileges or Immunities Clause might be the better way to go: “No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States.”

Thomas and Gorsuch are right, but they’re up against stare decisis. In one of its worst decisions ever, especially considering its context and implications, the Reconstruction Court in the infamous Slaughterhouse Cases of 1873 rendered the Privileges or Immunities Clause “a vain and idle enactment,” as Justice Stephen Field put it in dissent. Meant to protect “the natural and inalienable rights which belong to all citizens,” the Court majority read the clause as protecting only a few federal rights, like “the right to use the navigable waters of the United States.” There the clause has sat, all but “idle” ever since. One might think that result an embarrassment for conservative originalists, constitutional textualists as they generally are.

What then explains their refusal to override stare decisis, a principle at its weakest in constitutional adjudication. Hawley put his finger on it: progressive abuses of substantive due process. After the Slaughterhouse debacle, Fourteenth Amendment cases continued to come before the Court, of course. With the Privileges or Immunities Clause having been reduced to a nullity, however, the Court turned to the Due Process Clause, finally incorporating its protection for property rights in 1897, for contractual freedom in 1905, free speech in 1925, and so on, one right at a time. But after the New Deal constitutional revolution, the Court was largely deferential to the political branches and the states, until the mid-1950s when it got its second wind, and not a moment too soon in the case of civil rights, criminal procedure, and certain other rights. But at the same time, the Warren and Burger Courts were finding other “rights” that were nowhere to be found, even among the unenumerated rights the Ninth Amendment was written to protect. And that led to a conservative backlash and a call for “judicial restraint.”

It is that fear that lingers today among a fair number of conservatives, although in the last few decades, the debate has shifted on the Right, with ever more conservatives, prodded often by classical liberals and libertarians, recognizing the political infirmities of judicial restraint and, more important still, its constitutional inconsistency. For if textualism is originalism’s bedrock methodological principle, then judges cannot ignore the plain text of the Ninth and Tenth Amendments—they must be read together—or the Privileges or Immunities Clause of the Fourteenth Amendment. Rather than restrained, judges must be engaged. And that means, when necessary, informing the text with the rich natural rights and common law theory that stands behind it.

So Senator Hawley was right, eventually: The problem is with progressive abuses of substantive due process—with court’s finding rights nowhere to be found (and powers nowhere granted). Thus, the Griswold Court was right. The Connecticut statute that criminalized the sale and use of contraceptives, like the Texas statute years later in Lawrence that criminalized private same-sex sodomy, was enacted under the state’s police power, the power mainly to secure our rights. But in those cases, there were no rights to be secured—no plaintiffs who might have brought a civil suit or criminal complaint against the defendants—yet there were rights the statutes did infringe, our basic natural right to liberty, a right “retained by the people.”

Roe v. Wade, however, is a very different case, for the question there was whether the Texas statute at issue was indeed protecting rights, the rights of the unborn child. Here too the scope of the police power was at issue. Just after Samuel Alito’s 1985 Justice Department memo on abortion came to light—his 2007 Supreme Court confirmation hearings about to begin—I argued in the Wall Street Journal that because abortion at bottom is a criminal law matter concerning where to draw a line about which reasonable people can reasonably disagree, this police power question belongs with the states, which in 1973 were already drawing that line, in different ways, as they should have been left to do. That is a point that no less than then-Judge Ruth Bader Ginsburg made in her NYU Madison Lecture in 1993, two months before she was nominated for the High Court—and it almost nixed the nomination!

Thus, contrary to what too many conservatives have too long believed, it is hardly difficult for judges to read the text of the Constitution—the whole text—in light of the document’s structure and background assumptions and theory. Griswold, Lawrence, and similar cases, especially many involving economic liberty, are straightforward rights cases, easily decided by courts. Roe was more difficult, but in the end, because the inherent line-drawing belongs properly to the people and their state legislatures, absent egregious examples like those that would sanction infanticide, it was a federalism case.

Unfortunately, with the Slaughterhouse Cases, the Fourteenth Amendment got off to a bad start, and it’s never fully recovered. And the debate over substantive due process, a concept with roots in Magna Carta, has often only clouded matters. The Due Process of Law Clause will do the job, but it takes more work than many judges are prepared to do. As I wrote above, Justices Thomas and Gorsuch are right. The Privileges or Immunities of citizens of the United States Clause is the better route, because it takes us more directly to the Constitution’s text and, especially in light of the ample debates that produced it, to the natural rights theory that lends substance and legitimacy to our political and legal order.