Regarding so-called federal government power to regulate immigration, both Thomas Jefferson and James Madison, Madison generally regarded as the father of the Constitution, had written that no such delegation of power exists.
As mentioned in related threads, here is the relevant exerpt from Jefferson’s writing.
“4. _Resolved_, That alien friends are under the jurisdiction and protection of the laws of the State wherein they are: that no power over them has been delegated to the United States, nor prohibited to the individual States, distinct from their power over citizens. And it being true as a general principle, and one of the amendments to the Constitution having also declared, that “the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people,” the act of the Congress of the United States, passed on the — day of July, 1798, intituled “An Act concerning aliens,” which assumes powers over alien friends, not delegated by the Constitution, is not law, but is altogether void, and of no force [emphasis added].” —Thomas Jefferson, Draft of the Kentucky Resolutions - October 1798.
And here is the related excerpt from the writings of James Madison in Virginia Resolutions.
"That the General Assembly doth particularly protest against the palpable and alarming infractions of the Constitution, in the two late cases of the "Alien and Sedition Acts" passed at the last session of Congress; the first of which exercises a power no where delegated to the federal government, ...…
… the General Assembly doth solemenly appeal to the like dispositions of the other states, in confidence that they will concur with this commonwealth in declaring, as it does hereby declare, that the acts aforesaid, are unconstitutional; and that the necessary and proper measures will be taken by each, for co-operating with this state, in maintaining the Authorities, Rights, and Liberties, referred to the States respectively, or to the people [emphasis added]. ”— James Madison, Draft of the Virginia Resolutions - December 1798.
In fact, regardless that federal Democrats and RINOs will argue that if the Constitution doesn’t say that they cannot do something then they can do it, note that the Supreme Court has condemned that foolish idea. More specifically, the Supreme Court has clarified in broad terms that powers not expressly delegated to the feds via the Constitution, the specific power to regulate immigration in this case, are prohibited to the feds.
”From the accepted doctrine that the United States is a government of delegated powers, it follows that those not expressly granted, or reasonably to be implied from such as are conferred, are reserved to the states, or to the people. To forestall any suggestion to the contrary, the Tenth Amendment was adopted. The same proposition, otherwise stated, is that powers not granted are prohibited [emphasis added].” —United States v. Butler, 1936.
So while the idea that Obama cannot pardon illegal immigrants without the legislative support of Congress is at least conceptually correct, it remains that the feds cannot legislatively address any aspect of immigration without the required consent of the Constitution’s Article V 3/4 state majority via an immigration amendment to the Constitution imo.
The idea has been that one can't rule on naturalization without first ruling on immigration, and that is also covered in Art I, Section 8 when it says "To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof."
Is it possible to separate immigration and naturalization? I think so, but I also see how they are intricately connected.