4. “That to secure these rights, Governments are instituted among Men. . . .” Another overlooked line, which is of greatest relevance to our discussion of the first underlying assumption of the Constitution: the assumption of natural rights. Most emphasis today is placed on “the consent of the governed” passage that follows. But both parts of this sentence need to be reconciled. This part identifies the end of governments as securing the natural rights which the previous sentence affirms is the measure against which all government—whether of Great Britain or the U.S.—will be judged.
5. “. . . deriving their just powers from the consent of the governed.” Today, there is a tendency to focus entirely on this portion of the sentence to the exclusion of the first part, but we should recognize both parts are there and do not mean the same thing. Although the ultimate criteria of legitimate governance is the protection of natural rights, this affirms that particular governments only gain jurisdiction to protect these rights by the consent of those who are governed. The “consent of governed” is a different idea from protecting rights. It is how to get government up and running. But it is a problematic idea in terms of rights. If you emphasize consent and de-emphasize rights, government gets empowered to do anything in the name of the people, so long as it can claim the “consent of the governed,” which is never going to be the actual consent of each and every person. So there is a tension between the first and second parts of the sentence.The concept is inherently limited by a natural law context. This is true in Locke, too, although he is not as explicit: a social contract can't legitimately do anything that people happen to agree to do. It can't abrogate property rights, for example: for Locke, those are pre-political natural rights, and any state that presumed to invalidate them is no longer legitimate.
My own view of legitimacy is somewhat different, but I think I agree that natural law needs to be the foundation stone. If the Bill of Rights sets limits on the government -- or intends to do so, not that the government always listens or agrees to be so bound -- here is another, older, and more final set of limits. There are some things that no government can legitimately do.