If you are talking about muslims in general (not refugees but also tourists, foreigners etc.) than this would be an unconstitutional thing to do for the US in the first place and enforcing this would mean changing major definitions of the state's constitution.
The First Amendment is a restriction on government action, not a right granted to citizens. To not allow members of a specific religion to enter the country is pretty clearly prohibiting the free exercise of religion.
Immigration falls under administrative law and the plenary power given to congress and the federal government. The 1889 Chinese Exclusion Act was upheld as constitutional. The Smith Act of 1940 also allows for deportation of any alien affiliated with a subversive group (e.g., militant Islam).
The Bill of Rights applies to everyone. Citizen and non-citizen. This is because the Bill of Rights is meant to protect the rights of the minority from the majority. Not only that, but by restricting the passage of believers of a certain race would mean that the State is inhibiting a religion.
It's called the Lemon test, to determine if there is an appropriate "wall of separation" between Church and State. 1) The government can only get involved if they have a secular purpose
2) the law's effect should neither advance nor inhibit a religion, and; 3) it does not entangle the govt. and religious institutions in each others affairs.
The Chinese Exclusion Act was repealed by the Magnuson Act. The constitutionality and/or rights of congress to enact such a law wasn't struck down as unconstitutional by the courts, only repealed by subsequent laws.
Also, your phrasing implies that all Muslims are "foreign." Newsflash: there are 2.75 million American Muslims. Banning all Muslims from entering America is not only impossible in practice (not like you can test people's religions) but also will create divides in American society.
Banning a religion to enter a country is impossible, since the majority of foreign countries don't document an individuals religious affiliation. This would be comparable to the cold war where people where also falsely accused of being a communist since it wasn't actually written on a document.
The relative accuracy and method for religious identification relate to questions of efficacy and implementation, not whether the policy is right, unless you're presupposing a requirement that only easily enforceable policies/laws should be enacted.
Identifying religious affiliation is practically impossible to ever reach perfect accuracy and I am imposing the requirement to have a perfect accuracy in identifying it, otherwise the negative impact of false identification would be unavoidable.
The first amendment restricts the government from adopting a state religion or restricting religious practices among citizens. It grants little in the way of rights or restrictions on government power for foreign citizens, and restrictions on immigration would not be adoption of a state religion.
But the Declaration, which to be fair is not a legal document, was the writing down of the philosophical position of the same people who wrote the Constitution. In that document the claim is made that rights come from the Creator. Therefore these are not American rights, they are human rights.
Society could agree upon any particular document to define foundations for its political, philosophical, and legal framework. In the case of the US, the Constitution is agree to be that document, not the DoI. Further, the DoI lacks sufficient detail to serve as such.
The Declaration of Independence doesn't specify any rights that necessarily imply a right to free and unrestricted ingress for foreign citizens. "Pursuit of Happiness" could but doesn't necessarily imply such a right.
Leaving open the possibility that there are other unnamed rights does not logically imply the particular right you've assumed. E.g., To say "The Earth is among the set of planets with life" doesn't logically imply any other particular planet has life. It only leaves the possibility.
Militant members of ISIS are likely to be muslims, and also likely to wish to do harm to US citizens. Restricting entry of all muslims is then an imperfect step toward reducing the likelihood that ISIS members could enter the US and do harm to its citizens there.
*just giving the reasoning most have given for this belief for the sake of argument.
The argument: A(Militant members of ISIS) is probably B(a Muslim), and A is probably C(wishes to do harm to US citizens), therefore B is definitely C.
Just because ISIS recruits mainly from the Muslim population does not necessarily mean they have successfully managed to instil a hatred of US citizens in all Muslims.
Not only is preventing the movement of over a billion people pretty impractical, those billion people belong to a religion. A religion is an idea, a belief; it's not something you can visibly identify in all cases.
One last thought, the idea that preventing the passage of people who look like Muslims would fix anything is laughable. How many people actually think ISIS members would dress up in a suspicious manner? I think it's a safe bet that terrorists try to look like any other citizen to not draw attention.
Relative practicality doesn't mean an action is wrong. For example, a large scale war to end the Nazis' expansion and holocaust wasn't practical, but it may have been the right course of action. Claiming something may be difficult or can't be done perfectly doesn't show that it shouldn't be tried.
A restriction on immigration would only affect those seeking to enter the US -- probably a few orders of magnitude less than a billion. The burden of restricted travel to the US might not be very large and may collectively be less valuable than improved perceived safety and security of the US.
Your war example is fallacious. To declare war to Germany wasn't deemed impractical, the adjective you were looking for is called "difficult" or "challenging". In that case, whether it was right or not is not relatable.
This objection is one of semantics, and it fails to reject the point made. Additionally, impractical does not mean impossible, but it usually does imply difficult challenges. Also, many likely believed any given war to be impractical -- likely why the US entered that war so reluctantly.
That said, to propose a plan of action as a solution to a problem you have to actually have some idea of a plan. Just being practical here. As soon as this is announced, the public backlash will be swift and undeniable. But until we know that it is at least POSSIBLE, the benefits do not exist.
The vast majority of terrorism in America is caused by Christians. By similar logic, we should bar Christians from entering the country. Jews also commit more terrorist acts in America than Muslims, so we should ban them too.
Those could be argued to be good ideas. Yes, if we ban Muslim immigration we could apply the same logic to ban other religious groups. Unless you show that we should not ban others, you haven't shown that we should not ban Muslims.
I can't show that we shouldn't, except on moral grounds. I can, however, show that it's unconstitutional. This policy would violate the 1st and 14th amendment of the constitution.
1st because it's restricting the freedom of religion, 14th because it does not treat immigration applicants equally.
1st: Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
14th: [...] nor deny to any person within its jurisdiction the equal protection of the laws.
Any restriction on immigration or citizenship fails to treat people equally. If a religious restriction can't pass, any correlated legal restriction can achieve the same ends (e.g., nation of origin). If the debate is a legal one, legal alternatives aren't difficult to find.