As Mike Ramsey notes, the Cato Institute and the Alexander group were not the only Obergefell amici to discuss the original meaning of the Equal Protection Clause. David Gans's Constitutional Accountability Center also considered the issue, as Gans elaborates here. It is striking, however, how little of the CAC's evidence helps us learn what the words "nor deny to any person within its jurisdiction the equal protection of the laws" expressed during Reconstruction, the issue I discuss here and here.
The CAC cites first at p. 12 the Joint Committee on Reconstruction's reference to "the civil rights and privileges of all citizens in all parts of the republic," a close paraphrase of the guarantee of the "privileges or immunities of citizens of the United States," rather than the Equal Protection Clause. Next, the CAC cites at p. 13 Thaddeus Stevens and Jacob Howard's references to caste legislation and equality on the much-quoted pages 2459 and 2766 of the Congressional Globe. It is true that, like the CAC, most readers assign these discussions to the Equal Protection Clause, but as I have argued at length (see, e.g., here, citing my earlier discussions), Stevens and Howard can each can be read instead to refer to the Privileges or Immunities Clause. The CAC then quotes Henry Raymond's paraphrase (on the somewhat-less-quoted page 2502) of both the Privileges or Immunities and Equal Protection Clauses: "securing an equality of rights to all citizens of the United States, and of all persons within their jurisdiction." If anything, Raymond assigns priority to the Privileges or Immunities Clause in securing equality.
Like Cato (see here, also noting CAC's additional evidence), CAC at p. 19 cites newspaper evidence from the Chicago Tribune and Cincinnati Commercial, but this evidence plainly describes Fourteenth Amendment equality in terms of the privileges of citizens, rather than the language of the Equal Protection Clause.
Moving beyond 1866, the CAC cites at pp. 12-13 relatively late cases–the Civil Rights Cases from 1883, and Yick Wo from 1886. At pp. 13-14, however, CAC mentions an earlier case–Justice Field's reference to "hostile and discriminating legislation" as a circuit justice in the prisoner-haircut case, Ho Ah Kow v. Nunan, in 1879. That should ring a bell for scholars of the Privileges or Immunities Clause, for Justice Field used the same phrase–"hostile and discriminating legislation"–to describe the Clause's prohibition in his Slaughterhouse dissent. Moreover, even in Ho Ah Kow, Field stresses first the Privileges or Immunities Clause, not the Equal Protection Clause, in explaining why the Fourteenth Amendment contains such a ban. The quotation of Ho Ah Kow in the CAC brief at p. 14, for instance, refers to the "fourteenth amendment," rather than specifically to the Equal Protection Clause. (For more on Ho Ah Kow in the context of other opinions from Justice Field, see here at p. 286.) Justice Field is a very unlikely source for justification of the use of the Equal Protection Clause, rather than the Privileges or Immunities Clause, as the Fourteenth Amendment's generic guarantee of equality.
As I mentioned in discussing the Cato brief, the difference between using the Privileges or Immunities Clause and the Equal Protection Clause as a grounding for a ban on class or caste legislation may not matter much in Obergefell. For textualists, originalists, and anyone else who cares about precision in our discussions of "text and history," however, the difference matters a great deal.
Posted at 7:54 PM