Clark Neily argues that the Ninth Amendment and the 14th Amendment should be interpreted to protect so-called “unenumerated rights.” I find his argument confused and unpersuasive.
Let’s start with Neily’s claim that the Ninth Amendment’s “unambiguous text, purpose, and history” support the “concept of judicially enforceable unenumerated rights.”  Wrong on all counts, I believe. To reprise a longstanding debate with my libertarian friends:
Text: The Ninth Amendment reads (emphasis added): “The enumeration in the Constitution of certain rights shall not be construed to deny or disparage others retained by the people.”
By its express text, the Ninth Amendment merely sets forth a rule of construction governing other constitutional provisions. Its text cannot plausibly be read as a font of any rights. True, the Ninth Amendment presupposes the existence of “other [rights] retained by the people,” but the source of those rights must lie elsewhere. (The “unambiguous text” of Neily’s imagination would instead have to read something like: “Notwithstanding the enumeration in the Constitution of certain rights, there are other undefined rights of the people that shall not be infringed.”)
History and purpose: The history of the Ninth Amendment fully supports my textual reading. Defenders of the original Constitution argued against a bill of rights on the ground that such a listing would imply that the national government’s powers were far greater than they were. When the bill of rights was added, the Ninth Amendment was crafted to guard against this implication. In response to Edmund Randolph’s objection that the language of the Ninth Amendment should have stated that the existence of the bill of rights should not be construed to “extend the powers of Congress,” Madison wrote to George Washington that Randolph’s proposed distinction between preventing the extension of powers and protecting other rights was “altogether fanciful”: “If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended.” (I have used as a resource on this point the essay by Ninth Amendment scholar Thomas McAffee in The Heritage Guide to the Constitution.)
In other words, these “other [rights] retained by the people” referred to (but not granted by) the Ninth Amendment include the freedoms that are the correlative of the limited powers of the national government. They include as well the broad array of non-constitutional rights that state law is free to protect. Indeed, those who seem to think that any right that is really, really important must be constitutional engage in the very disparagement of non-constitutional rights that the Ninth Amendment is designed to guard against.
(For interested or skeptical readers, I’m pleased to take note of two law-review articles that have been published since my previous posts on the Ninth Amendment: Michael W. McConnell’s “The Ninth Amendment in Light of Text and History” (Ninth Amendment merely provides a “clear statement rule for abrogating unenumerated natural rights” and does not make those rights “supreme over positive law”) and Ryan C. Williams’s “The Ninth Amendment as a Rule of Construction” (Ninth Amendment “does not itself protect any rights from governmental interference, nor does it preclude treating ‘other’ rights differently from enumerated rights”).)
As for the 14th Amendment:
Neily oddly contends that the Privileges or Immunities Clause—“No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States”—protects unenumerated rights. But the Privileges or Immunities Clause is no different in nature, no less enumerated, than any of the rights-specifying provisions of the Bill of Rights. Each of those provisions, of course, presents interpretive questions as to its scope and meaning. For example, the question of what activities fall within “the freedom of speech” that Congress shall not abridge is no different in kind than the question of what activities are “privileges or immunities” that no state shall abridge.
I’m very open to Neily’s argument that the 1873 ruling in the Slaughter-House Cases badly misconstrued the Privileges or Immunities Clause and deprived it of the force it should have had and that the Court “tried to compensate for its misreading … by shifting much of the work that the privileges or immunities clause was designed to do … onto the due process and equal protection clauses.”  But that doesn’t change the fact that the text of the Due Process Clause (“nor shall any State deprive any person of life, liberty, or property, without due process of law”) is incompatible with the oxymoronic concept of “substantive due process”—with the notion that there are certain unstated interests in life, liberty, or property that the Due Process Clause protects from deprivation no matter what process is provided.