Someone has linked to a really nice legal review somewhere up in the comments, so my question is mostly answered now... but to answer your question about what I

Someone has linked to a really nice legal review somewhere up in the comments, so my question is mostly answered now... but to answer your question about what I see as a difference in wording above: If the law said "All citizens have the right to express their opinion" then a law saying "Non-citizens expressing their opinions will be punished" is OK. If, on the other hand, the law said "Congress will not make any laws restricting the expressing of opinions" (closer in wording to what we have) then a law saying "Non-citizens expressing their opinions will be punished" is no longer OK.