An originalist approach to due process can take several forms, and Justice Gorsuch's "surprise" decision in Dimaya v. Sessions reinforces this.
When I studied Constitutional Law some 40 years ago, the Slaughter-House Cases (1873) warranted scarcely a footnote. The scholarly consensus—including Raoul Berger’s Government by Judiciary (1977)—was that the “privileges or immunities” clause of the 14th Amendment had properly (or at least definitively) been relegated into oblivion, and hardly anyone mourned its demise. Instead, most academic interest focused on other language from the 14th Amendment—in particular the terms “due process” and “equal protection”—and on the Supreme Court’s mischievous use of those provisions to constrain the states’ exercise of their police powers, through the “incorporation” doctrine and “strict scrutiny” analysis.
No one, save perhaps a few libertarians (notably Roger Pilon), regarded the Slaughter-House dissenters as having made a persuasive case. As the majority noted, the dissenters’ open-ended interpretation—a harbinger of the Lochner era yet to come—would make the Court a “perpetual censor upon all legislation of the States,” effectively negating the concept of federalism and making federal judges (who were still regarded with suspicion in the wake of Dred Scott) the ultimate arbiters of public policy throughout the nation. This conclusion—in 1873 and until fairly recently—was considered preposterous.
Well into the 1980s, under the spell of what is now denigrated as the “old” originalism,” most conservative scholars shared the sentiment of University of Texas law professor Lino Graglia that the “privileges or immunities” clause is “one of those blessed constitutional provisions that by being ignored has not caused a single bit of trouble.” Not terribly long ago, incorporation was openly questioned, even if many skeptics conceded that stare decisis made doctrinal retreat impossible. Only outliers in the legal academy were concerned that the Slaughter-House Cases had rendered the clause “a vain and idle enactment,” as Justice Field lamented in his dissent. That was then.
Originalists have gotten “woke,” and–now styling themselves “new” originalists–have acquired an irresistible fascination for the once-moribund clause, and a renewed interest in exhuming a precedent that has mouldered in the jurisprudential ground for almost 150 years. Robert Bork pronounced that the clause “has been a mystery since its adoption and, in consequence has, quite properly, remained a dead letter.”  “New” originalists bristle at Bork’s assessment, urging ever more creative interpretations of the words “privileges or immunities” in an attempt to revitalize a clause that has become what Justice Scalia derisively called the “darling of the professoriate.” 
Perhaps no provision of the Constitution has received as much scholarly attention in recent years as the “privileges or immunities” clause, with a feverish pursuit to revisit—and overturn—the Slaughter-House Cases.
When I made light of this trend in a recent piece in American Greatness, I was surprised by the intensity of the reaction, from both originalist legal scholars and West Coast Straussians—both camps ostensibly conservative but increasingly resembling libertarians who favor an activist role for the judiciary. I responded to Mike Rappaport in this space (“The Many Flavors of Originalism”), which triggered replies from both Rappaport and his co-author, John McGinnis. Rappaport followed up with a full-blown critique of the Slaughter-House Cases, “The Unbearable Wrongness of Slaughterhouse.” The reaction of Harry Jaffa’s disciples (here and here) was predictable, given their wont for endless disputation, but the movement in the originalist camp—from “old” to “new”—warrants examination.
I am not the first—or only—dissenter on this subject, and commend the fine work done by the Hon. Stephen Markman, most notably his 2016 report for the Heritage Foundation, entitled “The ‘Judicial Holy Grail’: Why the Supreme Court Should Not Revisit the Privileges or Immunities Clause,” with which I agree and from which I freely borrow. Markman bluntly—but accurately—diagnoses the academy’s infatuation with the clause:
The continuing debate over the meaning of the clause is largely between factions of the “professoriate,” many of whom seem bent on conferring meanings to the clause that were never even remotely contemplated by its framers and ratifiers. The common result of these interpretations would be to further centralize and strengthen governmental power—in particular, that of the federal government at the expense of state governments and that of the judiciary at the expense of more accountable and representative branches of government.
To address my critics, I pose three questions. First, have scholars now “solved” the riddle of the clause? The answer is no (as Bork concluded long ago). The Heritage Foundation’s Guide to the Constitution states that “there is no agreement concerning a single original meaning of the Privileges or Immunities Clause.”  Markman concurs, as do others.  Rappaport questions whether I have read all the law review articles. I have not.  What I do know is that, despite the close attention of leading originalist scholars, past and present (such as Charles Fairman, Raoul Berger, David Currie, Philip Hamburger, John Harrison, Kevin Newsom, William Nelson, Michael Kent Curtis, Kurt Lash, and Michael Stokes Paulsen), no consensus has emerged from the scores of books and articles. Nor does such a consensus appear to be forthcoming.
When scholars reach such greatly disparate conclusions regarding the same inquiry, as Rappaport concedes, common sense suggests that there is no clear answer, not that there are “various alternatives” (some of which are “very plausible”). A fanciful theory is not an answer; it is more likely wishful thinking. The fact that no one can agree on the clause’s meaning strongly suggests it is indeed a mystery.
Second, should judges guess at the meaning of constitutional provisions when they are highly disputed (or even inscrutable)? Bork thought not. He famously said that “A provision whose meaning cannot be ascertained is precisely like a provision that is…obliterated past deciphering by an ink blot.”  Rappaport insists that there must be something under the ink blot, but Bork anticipated this objection: “There are, of course, academics who bemoan [the Slaughter-House Cases] and urge the Court to revive privileges and immunities, apparently on the theory that every part of the Constitution must be used, even if that means judges are writing their own Constitution.” 
The clause is not so much an ink blot as a Rorschach test—it means different things to different people based on their predilections and desires. Rappaport is puzzled that I can’t squint and find something in there I like—perhaps Harrison, or Lash, would be congenial? Rappaport is upset that I won’t play along with the “new” originalist gambit that “virtually everyone” is engaged in: “In the end, [Pulliam’s] position would be more convincing if he adopted one of these theories.” Pick a card—any card. Without clear textual or historical direction, judges who lack the discipline of restraint aren’t just guessing, they, too, can pick a card and find what suits them.
Third, is it consistent with judicial restraint to revisit a Supreme Court precedent a century and a half old because of a flurry of recent law review articles? Rappaport and McGinnis think so. I disagree. Not all scholars concur that the Slaughter-House Cases were wrongly decided, let alone “unbearably” so.  Many who disagree with the majority’s reasoning concur that the holding was correct, or at least that Justice Samuel Miller’s majority opinion was preferable to the egregiously-mistaken dissent. Depending on the interpretation du jour, some Slaughter-House critics acknowledge that—in the intervening 150 years—the Court has corrected the majority’s alleged error through other means: incorporation of the Bill of Rights via the due process clause, the recognition of “fundamental rights,” application of the equal protection clause, and so forth. Markman rightly asks: “Have not compensating interpretations of other provisions of the Fourteenth Amendment largely rendered irrelevant the missteps of Slaughterhouse?” If the alleged problem has been fixed, albeit on the “wrong” doctrinal grounds, is it really necessary to revisit a long-settled precedent?
Let’s be honest. The reason some “new” originalists want to exhume the “privileges or immunities” clause is that it represents fresh material for their cottage industry of increasingly esoteric constitutional theorizing. Bork understood this in The Tempting of America, and Markman put an even finer point on it:
The Privileges or Immunities Clause offers an opportunity to provide new meaning to the Constitution—not, to be sure, the meaning originally intended by its framers, for that has already been achieved by different means, but a genuinely new meaning and all without the bother of a new constitutional amendment. The purpose of revisiting the Privileges or Immunities Clause is to place something both “new” and “more” into the Constitution. It is to fill what is viewed as an empty vessel of a provision with something of consequence. It is to facilitate the attainment of the judicial “holy grail.”
In other words, the entire inspiration for this project is an unseemly eagerness to write on the blank slate that the clause represents. In this case, traditional precedent rules—do not overrule existing precedent absent clear error and for compelling reasons—do in fact restrain judicial activism.  Precedents that are 150 years old should be overturned only for the most compelling reasons, and the muddled disagreement with the Slaughter-House Cases does not rise to that level.
To paraphrase Rappaport, if one wants to pretend that the privileges or immunities clause has a clear, ascertainable meaning, one can certainly do it. But that ain’t originalism. It is simply the latest gloss on the living Constitution—the eternal quest for the judicial holy grail.
 Lino Graglia, “Do We Have an Unwritten Constitution? The Privileges or Immunities Clause of the Fourteenth Amendment,” 12 Harvard Journal of Law & Public Policy 83, 83 (1989).
 Robert H. Bork, The Tempting of America 166 (1990).
 Nelson Lund, “Two Faces of Judicial Restraint (or Are There More?) in McDonald v. City of Chicago,” 63 Florida Law Review 487, 511 (2011). Bork’s and Scalia’s disapproving attitude toward the “new” originalists’ current obsession may explain why these legendary jurists have been pushed aside (in the words of USD’s Steven Smith) “with a mixture of filial respect and condescending embarrassment.” Smith’s unpublished paper is entitled “The Old-Time Originalism.” Rappaport’s remark that “we have come a long way since Bork looked at these matters” is an example of this unwarranted disdain.
 David F. Forte & Matthew Spalding (editors), The Heritage Guide to the Constitution 501 (2d ed. 2014).
 See., e.g., David S. Bogen, “Slaughter-House Five: Views of the Case,” 55 Hastings Law Journal 333, 384 (2003) (“The intent of the framers remains a slippery concept with many plausible accounts competing.”).
 As if the “original public meaning” of words written over 150 years ago is just now being divined—like an epiphany—by the professoriate. Nor have I read every JFK assassination conspiracy theory, but having reviewed the Warren Commission Report and some supporting commentary, I reasonably conclude that Lee Harvey Oswald acted alone. The growing volume of conspiracy theories does not substitute for credible evidence.
 Bork, supra note 2, at 166.
 Id. (emphasis added).
 See, e.g., Michael Stokes Paulsen & Luke Paulsen, The Constitution: An Introduction 190 (2015) (decision was “probably correct”); Bogen, supra note 5, at 336 (“the majority acted correctly”).
 Moreover, the fact that libertarians have been fantasizing for decades about the cornucopia of judicially-created “unenumerated rights” the clause would unleash cannot be ignored.