In his latest column, Andrew Napolitano makes that claim in the title ("Foreign Policy is Not For the Courts to Determine").
Immigration is not about relationships between the US government and other governments ("foreign policy"). It is about the relationship between the US government (or perhaps other governments, for example state governments) and individuals wishing to enter and/or reside in the United States. That's not "foreign policy," it's "domestic policy."
Napolitano uses the mis-classification of immigration as "foreign policy" to question the standing of state governments to sue over Trump's order. But they clearly have exactly such standing. To explain why, we have to examine Napolitano's other big constitutional error in the piece:
A 1952 federal statute permits the president to suspend the immigration status of any person or group whose entry into the United States might impair public health or safety or national security. Trump exercised that authority in accordance with the 1952 law when he signed his Jan. 27 order banning all immigration from the seven named countries.
What's wrong with that claim? Simple: The statute is unconstitutional on its face. Long-time readers of KN@PPSTER know the sections of the Constitution I'm about to cite ...
Article I, Section 9: 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 one thousand eight hundred and eight, but a tax or duty may be imposed on such Importation, not exceeding ten dollars for each Person.
Article V: [N]o amendment which may be made prior to the year one thousand eight hundred and eight shall in any manner affect the first and fourth clauses in the ninth section of the first article ...
The Constitution did not include an enumerated federal power to regulate immigration. Therefore no such power exists (see Amendment 10).
Article I, Section 9 specifically reserved such a power to the states until 1808.
Article V forbade any amendment affecting that reservation prior to 1808 -- which, along with the lack of an enumerated federal power, makes it clear that an amendment would be required to remove that reservation of power from the states and/or transfer that power to the feds. And no such amendment has ever been proposed by 2/3 of both houses of Congress and ratified by 3/4 of the state legislatures.
This isn't just speculation. The matter was debated. Those provisions were put in the Constitution for a reason and that reason was simple: Without them it would never have been ratified. The slave states refused to ratify a Constitution that didn't protect the slave trade ("importation"). Pennsylvania refused to ratify a Constitution that didn't protect the availability of cheap non-slave labor for its growing manufacturing sector ("migration"). Both factions got what they wanted.
Congress abided by the Constitution's clear and unambiguous prohibition on regulating immigration until 1882 and even then hung the Anti-Chinese Exclusion Act on treaty provisions (co-equal with the Constitution) rather than on an activist Supreme Court's 1875 manufacture, out of thin air, of a federal immigration regulatory authority. And they were fairly cautious in expanding their unconstitutional portfolio for decades after that -- heck, you didn't even need a passport to enter or leave the US until after World War Two!
The statute that Napolitano refers to is clearly unconstitutional and therefore void and of no legal effect -- and the states which are suing against the order Trump tried to hang on that statute obviously have standing to sue against it as a violation of Article I, Section 9.
Note: As occasionally happens, I looked this over and decided the point was important enough to make in a Garrison Center column. So I did. Some of you have indicated interest in my writing technique, so this is an opportunity to compare quick blogging to considered op-ed, write to rewrite. The KN@PPSTER version ran to about 650 words. I decided to bring the Garrison Center version in at 400 words. Enjoy, if that's your kind of thing. Opinions on whether I managed to condense the argument without hurting it welcome.