SCOTUS agrees with me that immigration is not in the Constitution. Instead, SCOTUS has said that immigration falls under "inherent sovereign powers" of the federal government.
So, essentially SCOTUS has made up the fact that immigration can be controlled by the federal government, as SCOTUS notes the power is not found within the plain language of the Constitution.
http://tigerboard.com/boards/view.php?message=14847678
Throughout the history of the United States the Supreme Court has upheld all manner of federal statutes regulating immigration. By contrast, Supreme Court decisions preclude states from passing legislation that directly impinges on this area of federal dominion. The Supreme Court’s basis for action is clear when the area regulated is naturalization. Article 1, § 8, clause 4, of the United States Constitution specifically grants Congress the power to establish a "uniform Rule of Naturalization." By expressly allocating this power to Congress, the Constitution prevents the confusion that would result if individual states could bestow citizenship. The Constitution does not, however, explicitly provide that the power to deny admission or remove non-citizens rests with the federal government as opposed to state governments. Hence, in the early immigration cases the Supreme Court faced the problem of identifying the source of the federal government's exclusive and plenary power over immigration. Later cases found the plenary power to be an inherent sovereign power.