"Rule of Law" is a fantasy. It's a nice fantasy but it's still a fantasy. Generally it's as opposed to "Rule of Men." The idea (idea!) is that rather than have Individuals decide themselves what is legal or not legal (and therefore subject to imposition or punishment), the Laws will be written in as objective a fashion as possible. In this manner, no Individual will have the power to decide what behavior is or is not legal. The Law will spell it out and anyone who wields the power of the government, will not be able to use that power except in strict accordance with the Law.
We can easily see that it doesn't work, but why? It doesn't work because it's built on an assumption that is false-to-fact. On this planet, there are only people available to rule. No matter how much it's tried, those people are still Individuals and will always be driven by their own decisions and choices...their values. We can try to discern what their values and motivations are, but this is impossible. No person can know the totality of another's entire life experiences and the memories and beliefs that go along with that. So no matter how many Laws are created, the values and the choices of those Individuals are theirs and their alone. There is no escaping this fact, just as there is no escaping any fact. In the end, reality rules.
This is simple to see on the topic of gun laws. In a Constitutional Republic, this means that all Laws created by the government are subject to the First Principles as spelled out in the Constitution. If a Law--any Law--is in violation of the Constitution, then that Law is invalid and the force of Government may not be used to enforce it…at least not by Law.
With the Information Age, anyone can readily see that Rule of Law doesn't work, and gun laws are an easy way to see this. The Constitution of the United States says, very simply and clearly, that "the right of the people to keep and bear arms shall not be infringed." There is no ambiguity to that Law and so any infringement of that right is instantly and unambiguously in violation of it. Any law created by any institution is illegal---it is not consistent with the Highest Law of the land.
What of the rest, the part that mentions "a well-regulated militia"? The subject and the predicate of the sentence are easily discernible, so what of that clause? That too is unarguable as to its meaning. It is an explanatory clause, telling us why the main sentence is there. It is because, in the Founders words, a well-regulated militia is necessary to the security of a free state. It so happens that this is true, but it doesn't matter with regard to the reading of the main sentence. That stands on its own, with a clear subject and predicate. The additional clause is NOT a conditional nor qualifying clause. It does not say when or where or under what conditions, the main sentence holds true. It explains why no gun law is legal in this land, it does not mention when or how.
So every single gun law that's ever been concocted in this land is illegal. How could this happen? How could it be that a group of men (or women) manage to pass those laws anyway, and still physically enforce them?
That's what happens when people proceed with false-to-fact fantasies. On this planet, now and forever, there is no Rule of Law. There are only people available to rule others.