Regarding this post, Andrew Hyman comments:
There is much silence in Professor Upham's blog post about the Equal Protection Clause, which I think fully supports the decision in Loving [v. Virginia]. In contrast, I don’t think the Privileges or Immunities Clause supports that decision.
A right cannot plausibly be among the privileges or immunities of citizens of the United States if it is located nowhere else in the Constitution, and places no limit on Congress. This is not only plain from the text of the PI Clause, but was also the unanimous consensus in Dred Scott. Taney wrote: “The powers of the [federal] Government and the rights and privileges of the citizen are regulated and plainly defined by the Constitution itself.” Curtis wrote: “[T]he privileges and immunities of general citizenship, derived from and guaranteed by the Constitution, are to be enjoyed by….citizens of the United States.”
Those who want to interpret the PI Clause as a guarantee of unenumerated rights can find some support in the historical record, but it is relatively meager. And not incidentally it hands to liberal judicial activists an extremely powerful tool for controlling public policy by manufacturing new rights.
The Equal Protection Clause supports the Loving decision by its terms. A statute that was largely designed to place a mark of inferiority on mixed-race children was the essence of what the EP Clause was designed to prevent.
I tend to agree that the Equal Protection Clause is the most plausible source of marriage rights, but on the other hand couldn't one say marriage was a traditional privilege accorded generally to citizens by the states, so by the terms of the PI clause a state couldn't deny it to a subset of citizens (at least, without a good reason)?
Update: Andrew Hyman replies:
I would answer "yes" if the PI Clause instead said that no state can abridge the traditional "privileges or immunities of state citizenship." But instead the clause refers clearly to "the privileges of immunities of citizens of the United States." How can something be a privilege or immunity of citizens of the United States if it does not restrain Congress? As far as I know, folks like Processor Upham have not suggested that there's anything in the Constitution that requires Congress to allow official marriages and marriage licenses in the District of Columbia, for example. So, I have to answer "no" to your question.
Additionally, both Taney and Curtis very precisely distinguished constitutional rights rather than other (e.g. statutory) rights, as comprising the privileges and immunities of federal citizenship. The Fourteenth Amendment overturned Dred Scott, so why wouldn't the authors of that amendment have used the terminology that was used in that case without dissent?