First, the U.S. Supreme Court, in 2008, issued a highly publicized opinion, in Boumediene v. Bush, which, by itself, makes clear how false is the claim that the Constitution applies only to Americans.  The Boumediene Court held that it was unconstitutional for the Military Commissions Act to deny habeas corpus rights to Guantanamo detainees, none of whom was an American citizen (indeed, the detainees were all foreign nationals outside of the U.S.).  If the Constitution applied only to U.S. citizens, that decision would obviously be impossible.  What’s more, although the decision was 5-4, none of the 9 Justices — and, indeed, not even the Bush administration — argued that the Constitution applies only to American citizens.  That is such an inane, false, discredited proposition that no responsible person would ever make that claim.

What divided the Boumediene Court was the question of whether foreigners held by the U.S. military outside of the U.S. (as opposed to inside the U.S.) enjoy Constitutional protections.  They debated how Guantanamo should be viewed in that regard (as foreign soil or something else).  But not even the 4 dissenting judges believed — as Susan Collins and other claim — that Constitutional rights only extend to Americans.  To the contrary, Justice Scalia, in his scathing dissent, approvingly quoted Justice Jackson in conceding that foreigners detained inside the U.S. are protected by the Constitution (emphasis added):

Justice Jackson then elaborated on the historical scope of the writ:

“The alien, to whom the United States has been traditionally hospitable, has been accorded a generous and ascending scale of rights as he increases his identity with our society . . . .

“But, in extending constitutional protections beyond the citizenry, the Court has been at pains to point out that it was the alien’s presence within its territorial jurisdiction that gave the Judiciary power to act.” Id., at 770–771.

That’s from Scalia, and all the dissenting judges joined in that opinion.  It is indisputable, well-settled Constitutional law that the Constitution restricts the actions of the Government with respect to both American citizens and foreigners.  It’s not even within the realm of mainstream legal debate to deny that.  Abdulmutallab was detained inside the U.S.  Not even the Bush DOJ — not even Antonin Scalia — believe that the Constitution only applies to American citizens.  Indeed, the whole reason why Guantanamo was created was that Bush officials wanted to claim that the Constitution is inapplicable to foreigners held outside the U.S. — not even the Bush administration would claim that the Constitution is inapplicable to foreigners generally.

The principle that the Constitution applies not only to Americans, but also to foreigners, was hardly invented by the Court in 2008.  To the contrary, the Supreme Court — all the way back in 1886 — explicitly held this to be the case, when, in Yick Wo v. Hopkins, it overturned the criminal conviction of a Chinese citizen living in California on the ground that the law in question violated his Fourteenth Amendment rights to due process and equal protection.  In so doing, the Court explicitly rejected what Susan Collins and many others claim about the Constitution.  Just read what the Court said back then, as it should settle this matter forever (emphasis added):

The rights of the petitioners, as affected by the proceedings of which they complain, are not less because they are aliens and subjects of the emperor of China. . . . The fourteenth amendment to the constitution is not confined to the protection of citizens. It says:  “Nor shall any state deprive any person of life, liberty, or property without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.”  These provisions are universal in their application, to all persons within the territorial jurisdiction, without regard to any differences of race, of color, or of nationality; and the equal protection of the laws is a pledge of the protection of equal laws. . . . The questions we have to consider and decide in these cases, therefore, are to be treated as involving the rights of every citizen of the United States equally with those of the strangers and aliens who now invoke the jurisdiction of the court.

Could that possibly be any clearer?  Over 100 years ago, the Supreme Court explicitly said that the rights of the Constitution extend to citizens and foreigners alike.  The Court has repeatedly applied that principle over and over.  Only extreme ignorance or a true desire to deceive would lead someone like Susan Collins to claim that such rights are “protection[s] our Constitution guarantees American citizens.”

Second, basic common sense by itself should prevent people like Susan Collins from claiming the Constitution applies only to American citizens.  There are millions of foreign nationals inside the U.S. at all times — not only illegally but also legally:   as tourists, students, workers, Green Card holders, etc.  Is there anyone who really believes that the Bill of Rights doesn’t apply to them?  If a foreign national is arrested and accused by the U.S. Government of committing a crime, does anyone believe they can be sentenced to prison without a jury trial, denied the right to face their accusers, have their property seized without due process, be subjected to cruel and unusual punishment, and be denied access to counsel?  Anyone who claims that the Constitution only protects American citizens, but not foreigners, would necessarily have to claim that the U.S. Government could do all of that to foreign nationals.  Does anyone believe that?  Would it be Constitutionally permissible to own foreigners as slaves on the ground that the protections of the Constitution — including the Thirteenth Amendment — apply only to Americans, not foreigners?