The Constitution has little to do with promoting activities among the citizenry and way too much in the way establishing federal jurisdiction. However, even as the Constitution (1788) was an overreach of federal power fulfilling the statist dream, there still were no legal restrictions concerning immigration until the Page Act (1875), nearly 100 years after the Declaration of Independence. Citizenship requirements, though supremacist, enacted in the 1790's were so to establish residency, but the immigration laws decades later were put forth purely out of institutionalized racism.
In my opinion, saying that "Constitutional Liberty" grants the federal government "legal and moral authority" in this area is equivalent to saying that the Revenue Act (1862) grants the Treasury Department the legal and moral authority to take a percentage of an individual's wages. After all, it is Amurrika, dude. Amurrika.
Based on your defense of the "necessity" of "national law" in order to "acknowledge and preserve liberty," I am left with the impression that you are a nationalist. I am not.
P.S. You put words on my screen. I never said an individual be permitted to trespass. I recognize property rights. But who owns the borders? Who owns the coastlines? It's not you or I.
P.S. #2 I misspelled "corporatocracy" in my original comment.
"The rich man writes the book of laws the poor man must defend, but the highest laws are written on the hearts of honest men."