I'm not sure if noncitizens actually have the same rights as citizens or not. Free speech is a right, but any foreign national can be deported for no other reason than that we don't like what he's saying within our borders. Political contributions are a form of free speech, but we don't allow foreigners trying to influence our government in this way.
So, taking it to the extreme, does that mean that we could beat confessions out of foreigners? Possibly, possibly. It may be that we CHOOSE to extend the same protections to noncitizens, not that our constitution REQUIRES it.