So the Supreme Court somehow carved a First Amendment exception to the President just because of his role as the Commander-in-Chief? What should have more weig

So the Supreme Court somehow carved a First Amendment exception to the President just because of his role as the Commander-in-Chief? What should have more weight: a very specific prohibition on Congress (and therefore government) on abridging freedom of speech, or some vague thing called "National Security", a concept which by the way is not mentioned nor can be inferred at all anywhere on the constitution?