A little substantive law for this piece.
In the wake of the tragic events in both Paris and San Bernardino, Donald Trump raised the rhetoric, proposing not only to deport 11 million undocumented immigrants, but to also ban Muslims from entering the United States. In the first television advertisement of his campaign, the narrator of Mr. Trump’s ad states that Mr. Trump is “calling for a temporary shutdown of Muslims entering the United States, until we can figure out what’s going on.” (This verbiage was somewhat of a back-peddling from his earlier remarks for a “total and complete shutdown” of Muslims entering the United States.) New Jersey Governor Chris Christie also has a plan to bar Syrian refugees for the sake of national security.
In my opinion, and I am sure there are some of you who would disagree with me, Mr. Trump’s plan is un-American, inflammatory, and frankly stupid. But is a ban on Muslims entering the United States legal? Maybe, but I think the courts would have a field day with it.
Right out of the gate, most constitutional scholars loudly stated that a ban on Muslims from entering the United States would discriminate against a class of people based on their religion (not to mention to punish an entire class of people who have done nothing wrong). Certainly such a ban would violate constitutional guarantees of “due process of law” and “equal protection” for Muslim-Americans.
But what about those who are not U.S. citizens?
I don’t think anyone would argue that the United States, as a sovereign nation, has the authority to decide who may enter the country, and the conditions for entry by those who seek it. Most of this power lies with Congress, in its “plenary” power to control admission to the United States, how long a noncitizen is able to stay, and under what circumstances.
The Fifth Amendment of the U.S. Constitution provides that no person shall be “deprived of life, liberty, or property, without due process of law.”  The “due process” clause does not “acknowledge … any distinction between citizens and resident aliens.” This protection extends to U.S. citizens and noncitizens alike, provided that they have sufficient ties to the United States. So, noncitizen Muslims who are presently in the United States would seem to be protected. Those outside the United States, perhaps not so much.
What about the “equal protection” clause in the Fourteenth Amendment? The Fourteenth Amendment forbids the states from denying any person “equal protection” under the law. In 1886, the Supreme Court held that the “equal protection” clause is “universal in [its] application, to all persons within the territorial jurisdiction [of the United States], without regard to differences of … nationality.” More recently, in 1954, the Supreme Court held that this guarantee of equal protection is implicit in the Fifth Amendment’s “due process” clause.
So, the Fifth Amendment limits the federal government, and the Fourteenth Amendment limits the states. Again, it would seem that noncitizen Muslims who are in the United States are generally entitled the same protection under the law as U.S. citizens. But those outside the United States, that’s much less clear.
What about other grounds? Some constitutional scholars have argued Mr. Trump’s ban on Muslims would violate the First Amendment’s “establishment” clause. That provision forbids Congress from establishing an official religion. The argument goes that Mr. Trump’s policy would essentially require that the federal government make a determination as to who is really Muslim in order to know who to exclude from our borders, and that the “establishment” clause prevents the government from making these types of decisions.
If Congress were ever to take such a drastic step, and the issue thereafter reached the courts, it would be interesting to see what would then happen. The courts are required to apply “strict scrutiny” to all government actions that tend to discriminate on the basis of a “suspect class” (e.g., race) or upon a fundamental right (e.g., religion). Because strict scrutiny would apply, the courts will presume that such a law is unconstitutional, and the burden will then be on the government to provide a “strong basis in evidence” that shows the law achieves a “compelling” national interest and that the law is “narrowly tailored” to accomplish that goal.
Surely protecting against terrorism is a compelling national interest, but would such a law be the least restrictive means in order to do so? I’m not convinced.
One of the most famous Muslims (perhaps in the world) recently said of Mr. Trump’s inflammatory remarks, “True Muslims know that the ruthless violence of so called Islamic Jihadists goes against the very tenets of our religion.” Going on, this individual said that he believes “that our political leaders should use their position to bring understanding about the religion of Islam and clarify that these misguided murderers have perverted people’s views on what Islam really is.” Who was that? Muhammad Ali (a/k/a Cassius Clay). I could not agree more. Instead of Congress passing legislation to prevent Muslims from entering the United States, we should simply tone down the inflammatory rhetoric and educate ourselves as to what’s really going on here. Pure politics. Just a thought.
 The narrator goes on to say that Mr. Trump will “stop illegal immigration by building a wall on our southern border that Mexico will pay for.” I’ll save my commentary on this one for another day.
 U.S. Const. amend. V.
 Kwong Hai Chew v. Colding, 344 U.S. 590, 598 n.5 (1953).
 See Verdugo-Urquidez v. United States, 494 U.S. 259, 270-71 (1990) (“[A]liens receive constitutional protections when they have come within the territory of the United States and developed substantial connections with this country.”). However, aliens who are outside the United States are generally not afforded this constitutional protection. Id. at 269 (“[W]e have rejected the claim that aliens are entitled to Fifth Amendment rights outside the sovereign territory of the United States.”) But see Ibrahim v. Department of Homeland Security, 669 F.3d 983, 997 (9th Cir. 2012) (an alien not currently in the country, but who had been lawfully present in the United States for four years before departing the country and who was latter prevented from returning, had established a “significant voluntary connection” to the United States sufficient to assert claims under both the First and Fifth Amendments).
 Yick Wo v. Hopkins, 118 U.S. 356, 369 (1886).
 Bolling v. Sharpe, 347 U.S. 497 (1954).