Interpretations of the words change. The words themselves, without a vast majority of people and states, do not change.
Re. Guns, it's not a different topic at all. The constitution is the reason why no American government is able to ban guns. No American government will, while the second Amendment holds.
So yes it is fundamental to the gun debate.
The constitutional stasis is cause death after death after death of the citizens it is meant to protect.
To anyone new reading:
Heresy? Am I offending you?
How Holy are you regarding words made by politicians and soldiers of the past?
If you're offended my case gains further proof.