It is not at all obvious that this is true. I think it's highly unlikely given that the federal government has almost unrestricted ability to pass laws about personal rights (either strictly or in practice, see the federal drinking age of 21, smoking, etc).
I agree that it’s not obvious that such a law would actually be unconstitutional. I just think this court has become an unapologetically partisan body.
Even if it was, there's no reason not to test it.