I’m not really addressing Matt Franck’s discussion, which seems bulletproof to me, I just like saying “Ptolemaic epicycles of abstruse constitutional reasoning” and wish I were smart enough to have come up with it.

To me, the McCain citizenship business seems, as Matt and Jonah suggest, frivolous. A more interesting issue is raised in David’s post, to wit: What is the effect of Congress legislating in a way that gives content to provisions of the Constitution?

I don’t think it’s true that “Congress cannot define a constitutional term by statute.” Each branch of our government has an obligation to interpret the Constitution in carrying out its duties, and Congress does occasionally purport to define constitutional terms by statute. For example, Section 2381 of Title 18, U.S. Code, defines and sets out the requirements for proving treason, notwithstanding that treason is defined in Article III, Section 3.

What Congress may not do is two-fold. First, it may not legislate against the terms of the Constitution. For example, if the treason statute had attempted to undo the Constitution’s two-witness treason rule, the statute would be unconstitutional. Second, Congress may not attempt by statute to reverse a Supreme Court interpretation of a constitutional provision — at least that’s what the Supreme Court says, on the theory that it is an aspect of the judicial power to say authoritatively what the law is. (There is nothing in the Constitution that explicitly says Congress may not reverse the Court’s constituitonal constructions; as I understand it, the Court assumed the mantel of finality in the course of defining the “judicial Power of the United States,” which the Constitution expressly vests in the Supreme Court.)

Congress, for example, tried in the Religious Freedom Restoration Act of 1994 to reverse the Supreme Court’s interpretation of the First Amendment’s Free Exercise Clause. RFRA was later invalidated (at least in part) in City of Boerne v. Flores (1997). Here is what Justice Kennedy’s majority opinion instructs:

When Congress acts within its sphere of power and responsibilities, it has not just the right but the duty to make its own informed judgment on the meaning and force of the Constitution. This has been clear from the early days of the Republic. In 1789, when a Member of the House of Representatives objected to a debate on the constitutionality of legislation based on the theory that “it would be officious” to consider the constitutionality of a measure that did not affect the House, James Madison explained that “it is incontrovertibly of as much importance to this branch of the Government as to any other, that the constitution should be preserved entire. It is our duty.” 1 Annals of Congress 500 (1789). Were it otherwise, we would not afford Congress the presumption of validity its enactments now enjoy.
Our national experience teaches that the Constitution is preserved best when each part of the government respects both the Constitution and the proper actions and determinations of the other branches. When the Court has interpreted the Constitution, it has acted within the province of the Judicial Branch, which embraces the duty to say what the law is. Marbury v. Madison, 1 Cranch, at 177. When the political branches of the Government act against the background of a judicial interpretation of the Constitution already issued, it must be understood that in later cases and controversies the Court will treat its precedents with the respect due them under settled principles, including stare decisis, and contrary expectations must be disappointed.