Non-citizens do have rights under the Constitution, so long as they are in the United States.  The 14th Amendment says that "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."  Notice it merely says "person" and not "citizen."

Of course, this only applies to non-citizen who are in the United States ("within its jurisdiction").  It would not apply to, for example, Assad, who is in Syria.

Non-citizens do have rights under the Constitution, so long as they are in the United States.  The 14th Amendment says that "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."  Notice it merely says "person" and not "citizen."

Of course, this only applies to non-citizen who are in the United States ("within its jurisdiction").  It would not apply to, for example, Assad, who is in Syria.

yeah but the constitution clearly defines its scope to only extend to citizens, too.  You're reading too much into the word "person."
As I recall, however, current laws do extend certain rights to non-citizens, after Guantanomo.  The general argument was that they could be held indefinitely because they weren't citizens and therefore not entitled to constitutional rights, but the Supreme Court interpreted the framers' intentions as including all persons as having a basic habeas corpus right (which is not an unreasonable assumption, given that the principle far predates the framers, and even the reformation).  Ergo, certain aliens do have certain rights even under American law.