Apparently inspired by CalPundit’s idea to “out” anti-gay Republicans, Matthew Yglesias is speculating on the prospects of a right-to-privacy bill or amendment. Matthew speculates on why such an amendment has not been proposed in the past:

The existence (and scope) of a right to privacy in the constitution is a matter of some controversy, and proposing a constitutional privacy amendment might be seen as an admission on the part of privacy advocates that such a right does not exist in the un-amended constitution.

This argument goes back to the days of the Federalist Papers; one of the reasons why the Constitution didn’t originally include a Bill of Rights was the fear that enumerating rights would imply that those not enumerated did not exist (this is the reason the 9th Amendment was added to the Constitution, as part of the compromise Bill of Rights that the Federalists proposed to get the Constitution ratified—Radley Balko gives the expanded explanation here), based on the understanding that Congress’s enumerated powers were narrowly-drawn. Alexander Hamilton makes this argument in Federalist 84:

I go further, and affirm that bills of rights, in the sense and to the extent in which they are contended for, are not only unnecessary in the proposed Constitution, but would even be dangerous. They would contain various exceptions to powers not granted; and, on this very account, would afford a colorable pretext to claim more than were granted. For why declare that things shall not be done which there is no power to do? Why, for instance, should it be said that the liberty of the press shall not be restrained, when no power is given by which restrictions may be imposed? I will not contend that such a provision would confer a regulating power; but it is evident that it would furnish, to men disposed to usurp, a plausible pretense for claiming that power. They might urge with a semblance of reason, that the Constitution ought not to be charged with the absurdity of providing against the abuse of an authority which was not given, and that the provision against restraining the liberty of the press afforded a clear implication, that a power to prescribe proper regulations concerning it was intended to be vested in the national government. This may serve as a specimen of the numerous handles which would be given to the doctrine of constructive powers, by the indulgence of an injudicious zeal for bills of rights.

James Madison, who did support a Bill of Rights in some form, makes a similar point in a letter to Thomas Jefferson, again couching it terms of limited federal powers and a fear that enumerating liberties might encourage them to be curtailed.

Having said all that, in the 215 years since the Constitution was ratified, the interpretation of Congress’s enumerated powers has greatly expanded. Unless you’re a liberal who subscribes to Lopez (a rare liberal indeed!), an enumerated powers argument in support of a right to privacy isn’t going to go anywhere—despite the fact that, at least when discussing the federal government (and state governments whose constitutions also enumerate the powers of their legislatures, a field I am admittedly inexpert on), it’s arguably the most powerful one. So necessarily the protection of unenumerated rights rests solely on the 9th Amendment, which leads to the need to enumerate them to protect them from infringement by judicial or legislative fiat unencumbered by any recognition of limited power.

My view: since both parties have basically abandoned the principle of limited government, as a practical matter a RTP amendment probably wouldn’t be a bad thing in this day and age, as the 9th is a very shaky foundation to found fundamental freedoms, including some conception of a right to personal privacy, on. However, I’m not quite ready to abandon that principle myself, so from a philosophical standpoint a privacy amendment would likely be another nail in the coffin of the 9th.

Edited add a link to Radley’s 9th Amendment discussion, which I read and linked a day or two ago (a similar discussion been a part of my 101 lecture on the Constitution for a few years); Jeremy Scharlack has a good roundup of links on the 9th too. More Santorum discussion in the Santorarium.