While blocking the temporary travel bans issued by President Trump on foreigners entering the United States from a small number of Muslim nations, the lower federal courts have used arguments that could be adopted by the current (or a future) Supreme Court to reinterpret the Constitution in a way that, effectively, would open the nation's borders to immigration beyond the control of either Congress or the president.

The Supreme Court (following the lead of lower federal courts in some instances; taking the lead in other instances) has a long record of gradually reinterpreting the Constitution in a series of cases over the course of several years.  In general, the Court introduces seemingly minor (but in fact, highly significant) changes to constitutional law in a few cases, and the Court then cites those earlier cases (and not the Constitution) as the authority for imposing major changes in a later case.  In other words, the Court cites itself as the authority for its decisions.  The death penalty, abortion, and gay marriage are three of the more prominent examples where the Court has used this technique to radically transform American law and impose Progressive-liberal ideology on the entire nation, without a shred of support for the change to be found in the Constitution's text or history.

Now, with regard to President Trump's second travel ban (which replaced the first one), the U.S. Court of Appeals for the Fourth Circuit has claimed that it likely violates the Constitution; specifically, the First Amendment's establishment clause, which prohibits the government from establishing a religion.

However, three of the Fourth Circuit's own judges acknowledged that "the Supreme Court has never applied the Establishment Clause to matters of national security and foreign affairs."  Moreover, the judges noted that nonresident foreigners, including relatives of U.S. citizens, "do not have rights of entry [into the United States] or any Establishment Clause rights."

Nevertheless, the Fourth Circuit, among other things, accepted the argument that by delaying or denying Muslims (in foreign nations) entry into the United States, the travel ban would injure Muslims in the United States.  Decades ago, communists in the United States attempted to use a similar argument, claiming that by denying communists (in foreign nations) entry into the United States, the federal government was depriving American communists of what they alleged was their First Amendment "right" to hear and meet foreign communists in person.  The Supreme Court, though, did not accept the argument.

Today, even if the government banned every single foreign Muslim in the world from entering the United States, the ban would do nothing to establish a religion in the United States, and the ban would do nothing to prevent any American from the free exercise of religion in the United States.  Which religion would an entry ban establish?  Christianity?  Judaism?  Zoroastrianism?  How?

Of course, in reality, any claim that a ban of foreigners would establish a religion in the United States has to rely entirely on a modern reinterpretation of the establishment clause and redefinition of what constitutes an establishment of religion.

In short, under the Constitution, the federal government (specifically, Congress) has the power to deny any individual alien or any class of aliens entry into the United States on any grounds.  The Supreme Court itself has upheld the exclusion of aliens based on race, national origin, political association, belief system, and other such factors.  Indeed, the Court has said that "Congress regularly makes rules [for aliens] that would be unacceptable [under the Constitution] if applied to citizens."  And under federal law (namely, the Immigration and Nationality Act), Congress has delegated some of its power over aliens to each president.

While the purpose of President Trump's travel ban is to protect the nation from terrorists, the federal government has always had (at least until now) the power to ban foreigners based on their belief system.  To repeat, the Supreme Court itself has upheld the exclusion of foreign communists.

Like communism and fascism, Islam is a belief system with principles that violate the rights of individuals.  And if the government, in the national interest, banned foreigners who are followers of Islam, the government would not be acting for the purpose of advancing religion any more than if the government banned followers of communism or fascism; the purpose of such a ban would be secular.  The government would be treating a "religious" belief system (Islam) the same as it treated a nonreligious belief system (communism).

Yet with regard to the travel ban, the Fourth Circuit argued that it was "steeped in animus."  This is utter nonsense.  Is opposition to communism and fascism based on animus?  Opposition to Islam is based on knowledge, not animus.

Additionally, the Fourth Circuit argued that the travel ban hurts the "feelings" of Muslims.  This is beyond irresponsible.  It is indefensible to argue that the government cannot criticize or disapprove of a belief system, its principles, and its practices.  The founding document of the United States, the Declaration of Independence, proclaims that governments are instituted to secure the rights of the people.  When a belief system threatens or undermines the securing of these rights, it is not only legitimate for the government to criticize and disapprove of the belief system, but it is the duty of the government to do so.

Notably, in a separate decision by a different federal court, the U.S. Court of Appeals for the Ninth Circuit claimed that the travel ban violates a federal law, the Immigration and Nationality Act, because the executive order that implements the ban exceeds the president's authority.  However, since the Ninth Circuit's decision is based on federal law, not the Constitution, it does not have the same (potential) consequences as the Fourth Circuit's decision, because it does not prevent Congress from passing, or the president from signing, a new law that provides such authority.  Nevertheless, the Ninth Circuit erred by refusing to uphold the ban; the executive order is a valid exercise of President Trump's authority.

The Supreme Court could settle this issue (for the short term) first by lifting the injunctions that have blocked the ban, and then by upholding the ban.  Alternatively, the Court could refuse to uphold the ban, and instead adopt the arguments that were used by the lower federal courts.  Moreover, even if the Court upholds the ban, a future Supreme Court could at some point still adopt the arguments that were used by the lower federal courts.  The Court could reinterpret the First Amendment by declaring it unconstitutional for either Congress or the president to deny foreigners entry into the United States on certain grounds, such as their belief system.  Ultimately, such an outcome would take away from the federal government and give to foreigners a power over who enters the nation.

Paul Pauker is the author of Morality and Law in America. He also runs a site dedicated to advancing the unalienable rights to life, liberty, and property.