According to the Constitution “The migration or importation of such persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the year to the year 1808, but a tax or duty may be imposed on such importation, not exceeding ten dollars for each person”.
The basis for this and the framework in which it was constructed were the original 13 colonies, now states, whose borders stopped essentially at the Appalachian Mountain chain. The remainder of the country was either claimed, illegitimately by England, France or Spain, including Spanish Florida that is east of the Appalachians. It was intended to put a stop to slavery. From then on out the States had to grow their own populations by the normal means, including those already here as slaves.
One can interpret the terms “States now existing” meaning only the 13 original States and this interpretation hinges on how the term “now” is employed. The Constitution made provision for the inclusion of additional States and how were these states to admit anyone as citizens if “now existing” was restricted to the original 13 States? Therefore the “now existing” really meant all the States then admitted to Union. It still meant the Congress could prohibit the importation of anyone, whether the States wanted to admit them or not.
The federal government’s actions, first to limit migration by numbers and by country of origin was a violation of the power given the Congress. Its failure to enforce its own illegal acts has allowed millions to not only enter the country but to remain here. All they have to do to become a citizen of the United States is to be resident for a certain period of time and pass a test in English and swear allegiance to the United States.
The vast majority of these immigrants, legal and illegal come here because of economic persecution or lack of employment opportunities. In any event it is not political but economic persecution by the dominant ethnic or religious entity that rules the country and favors their own.
The question then becomes what to do with those already here? Their country does not want them back as evidenced by the fact that countries, such as Mexico, do not want them back and actually encourages and assists them in leaving because its economy cannot support them. Unfortunately, our ignorant government has not included in its recognition or treaties with other countries that they shall take back any of their citizens we do not want to take up residence in our country. I should point out that these illegal entrants have not broken any law, except that of trespass and this is not a judicable offence with a right to appeal. The politicians have made it so, unconstitutionally, in order to provide income for their fellow lawyers, just as they have by the mistaken assumption that a right to an attorney means that the government (people) must provide it if you cannot afford it.
The legal and moral answer is to make citizens of all those whom the State in which they reside wishes to accept and return all others to their country of origin. The first is complicated by the fact that those unable to support themselves or who are on welfare are given this primarily by the federal government. Acceptance by the State should be conditioned on the State footing the entire welfare bill for those they wish to accept as citizens. See how many the people of the State would be willing to take in under these circumstances.
This whole mess would have been avoided if the government followed the Constitution in the first place. The greedy wanted cheap labor and they got it, first with slavery and later with the allowance of labor, including management to steal from those who employed them, all courtesy of Franklin Roosevelt and his Democrat (Progressive) Supreme Court.