Any time that three-fourths of the states vote in favor of a proposal, the Constitution can be changed - and rightfully so since it would reflect the will of an overwhelming majority of the public.
The Constitution defines the powers of the federal government and the Bill of Rights contained extra prohibitions for the federal government to stay out of specific areas in which it was not granted any power. The "Old West" laws were not unconstitutional because they were not federal laws; each state's constitution and laws determined the extent of the RKBA and permissible regulations in the respective states. The very recent incorporation of the 2nd Amendment against the states makes the legal landscape ... more interesting.
That's it, yeah that makes perfect sense. Very well thought out post and certainly better than my Eggnog soaked brain could have done.