If you live in the U.S, or you keep up with U.S politics, you've probably heard how state governors aren't allowing Syrian refugees into their states, and some politicians only want to allow Christan refugees into the U.S. This led me to wonder, is it legal to deny a refugee, or immigrant based on their religion?
My assumption: the U.S. government is considering whether to accept refugees and immigrants (given your Syria comment). The background section talks about State attempts to restrict entry.
The answer is nuanced since there are different standards for an entrance decision than there are for someone who is already in the U.S. This is because foreign nationals in their home nations aren't "persons within the jurisdiction of the United States," and so laws like the Civil Rights Act only apply in spirit. What does that mean?
We wouldn't expect to see the federal government discriminate based on religion, but we might expect to see decisions made about groups that incidentally share an common religion.
This is because the federal government has wide latitude when it comes to alienage---which is just a formal name for policies related to non-citizens. While religion is afforded a high degree of protection, the federal government's alienage policies are governed by the lowest level of judicial scrutiny. This implies a practical challenge: things like religion and national origin can be very difficult to disentangle from questions that pertain to the alienage category. For example, a policy might restrict some group's entry "because of" a particular alienage reason and "in spite of" the fact that most of the affected people happen to share a common religion.
The Equal Protection Clause U.S. Const. Am. XIV § 1 prohibits States from denying any person within its jurisdiction "equal protection of the laws." The Clause is often applied to the federal government as well, via the Due Process Clause U.S. Const. Am. V. See, e.g. Bolling v. Sharpe, 347 U.S. 497 (1954).
In relation to the clause, laws are reviewed for their constitutionality using either strict, intermediate, or rational basis scrutiny. Strict scrutiny would mean that in order to distinguish based on a particular trait, the government has to have a compelling, narrowly tailored interest, and no less restrictive alternative available. Rational basis just means the government's interest is subject to a lower level of scrutiny (e.g. benefits exceed costs, or don't let in felons). Things like, race, religion, national origin, and some forms of alienage are suspect classes that merit strict scrutiny.
This bit about alienage is important. As we'd expect from the above, when States enact alienage statutes, they're subject to strict scrutiny, and when those statues cross the line, the courts have found that State attempts to restrict resident or non-resident aliens encroach upon the federal government's exclusive control over entrance of aliens. Graham v. Department of Pub. Welfare, 403 U.S. 365 (1971). In other words, the federal government, not the States, decides whether various "aliens" are admitted. Note: State scrutiny levels when dealing with undocumented immigrants may be context specific. See, e.g. Plyler v. Doe, 457 U.S. 202 (1982) (children and education).
The federal government's authority over immigration is further solidified by the Supremacy Clause of the U.S. Const. Article VI. See Mathews v. Diaz, 426 U.S. 67 (1967). As such, the courts have applied rational basis scrutiny to the federal government's immigration policy.
One reason alienage is interesting is that it tends to encompass things like national origin and religion. This doesn't imply the federal government makes its decisions on the basis of religion. In fact, it'd be hard to make an argument that they do. However, since the categories can be so closely entwined, many scholars have argued for a change in standard.
In hindsight, this topic seems quite forward looking. A couple weeks after the OP's question a U.S. presidential candidate (Donald Trump) came out in favor of a ban on entry into the U.S. by Muslims. That led to a flurry of activity, and to this insightful blog post by Professor E. Posner.
The granddaddy of civil rights legislation is the 1964 Civil Right Act. It prohibits discrimination based on race, color, religion, national origin with respect to:
- Most hotels, motels, restaurants, theaters, and public accommodations engaged in interstate commerce
- Access to state and municipal public facilities
- Public schools
- Most programs that are federally funded.
- Most employment settings
The provisions of this act are in the US Code: https://www.law.cornell.edu/uscode/text/42/chapter-21
The Act itself is here: http://www.senate.gov/artandhistory/history/resources/pdf/CivilRightsActOf1964.pdf
A source of unknown authority describes it here: https://en.wikipedia.org/wiki/Civil_Rights_Act_of_1964#Title_I
Discrimination based on religion under the Constitution as ratified and understood within the ratifying conventions is acceptable. So called Constitutional “Law” is self-evidently unconstitutional for it violates separation of powers. Courts cannot make laws. This erroneous concept was enhanced with a doctrine created by the Court in the early 20th century; that doctrine being the Incorporation Doctrine.