More of me Thinking out Loud - a response to someone on FB calling for a reinterpretation / nullification of our 2nd amendment.

Jefferson would be shocked by a lot of things in this century. I have heard the arguments stating that the US Constitution is a "living document". I believe Jefferson and most other men who signed that document would scoff at that idea.
Boiled down to its most basic elements that idea means the Constitution is or can be pretty much anything a ruling politician or political party wishes it to be at any given moment. It basically nullifies the codification of Rule of Law and puts everything into a container of whimsical and arbitrary rule - which is to say Gov't itself would function exactly like a Monarchy.
The "law" would be whatever the ruling class wants it to be at any given time.
The SCOTUS seems to disagree with your views on the 2nd amendment. No need for me to say anything further about that.
Where you and I might agree is that people ought to know better than to carry firearms while carrying out their 1st amendment right to demonstrate.
The finer point here is not "what the law says" because you and I both know that we all - you, me, certainly politicians - try to bend it (the law) according to our own personal ideas and wants; no the finer point is that our "God given Rights" indeed our very privileges as Citizens of USA come with a burden of personal responsibility.
That is to say we hold the responsibility to act as Americans first and foremost and above our impulses to carry on as a bunch of self identified special interest groups. I think that would be appalling to Thomas Jefferson. I think Jefferson would be shocked to see people actively trying to destroy USA by eroding its moral character - or at least the set of morals upon which Jefferson et al attempted to use as a foundation upon which to codify a "Just" and righteous Nation of by and for The People.
I think the people who carry firearms while demonstrating SHOULD BE BETTER - KNOW BETTER. But like the people who choose to trample on our Flag; "take a knee" during the singing of the National Anthem, Say the most outrageous, libelous, hateful things about the POTUS (or anyone with whom they disagree politically) I disagree with them but I defend their constitutional Rights to do so. Just because a person has a Constitutional Right to do something does not make it a good idea to do certain things in certain places at certain times.
One thing I learned fairly early in life is that "common sense" really is not common - at all. Too many people operate on and act on their emotions all too often - IMHO more often than not.
I agree with you and others who worry that sooner or later "something bad" is likely to happen when people carry firearms while demonstrating. But I don't think it's a good idea to nullify the 2nd amendment over things that "might" happen.
Short of a condition of legally called Martial Law I do NOT think it's a good idea to disarm the American People. Gov't overreach, and abuse of gov't power are always prescient. I am reminded of the tragic shooting at Kent State back in 1970 (?) - that is a perfect example of a politician making a grave error in judgement. But more importantly, it is a perfect illustration of how quickly the Gov't - our own Gov't officials can and WILL turn violent against We the People. Which is really at the heart of why the 2nd amendment exists in the first place.