Well, actually the debate over the second amendment's meaning, from a historical, contextual, semantic and comparative perspective is settled. The vast majority of serious second amendment scholars are of the opinion that the second amendment recognizes an individual right of arms ownership. Of the 30+ substantive law review articles about the second amendment published since 1980, only a couple have come to a different conclusion. Even many scholars who are personally against an individual right have reluctantly come to the conclusion that's what the second amendment was meant to recognize (but they aren't happy about it). We can accept as settled constitutional law such a right irrespective of the opinions and efforts of politicians and some jurists (such as Justice Ginsburg) to the contrary. (By the way, the term "well-regulated", in the parlance of the times, meant "well-trained" or "competent", not "heavily controlled".)
We also need to consider the fact that an armed society is the final barrier to totalitarian rule. It is a historical fact that totalitarian regimes have had to disarm their societies before they could start their mass slaughter - think of the Khmer Rouge or the Nazis, for starters. While the possibility of totalitarianism may seems remote in America today (or not, depending on your view), the fact is that an armed society is what ultimately prevents (or will prevent) it from becoming a reality. As United States Ninth Circuit judge Alex Kozinski said not too many years ago:
The prospect of tyranny may not grab the headlines the way vivid stories of gun crime routinely do. But few saw the Third Reich coming until it was too late. The Second Amendment is a doomsday provision, one designed for those exceptionally rare circumstances where all other rights have failed--where the government refuses to stand for reelection and silences those who protest; where courts have lost the courage to oppose, or can find no one to enforce their decrees. However improbable these contingencies may seem today, facing them unprepared is a mistake a free people get to make only once.
It is inconceivable to me that the founding fathers, who had just thrown off a government by force and by arms - a government that was hardly totalitarian by today's standards, did not have this thought in mind when they enshrined the right to keep and bear arms in the second of ten constitutional amendments (the ten amendments that compose the Bill of Rights are not randomly ordered).
An Even More Fundamental Right
A right that is so fundamental, so common-sensical, so viscerally obvious, so long-established, so humanistic, and so necessary for a just society that it needed no enumeration in the Constitution or Bill of Rights is the right to self-defense. It would no more occur to the founding fathers (or anyone of the time) that a right to self-defense needed to be recognized than a "right to eat" needed to be. And yet today we have arrived at the point where the right to self-defense is under attack (no pun intended) from seemingly every quarter.
Individual self-defense is impossible in many cases without weapons, including firearms. This point is so obvious that I will treat it as self-evident. Thus, in order for citizens to exercise a right that has been recognized since long before the United States existed, they need to also have the right to own and carry arms appropriate for self-defense. You cannot simultaneously assert a right and deny the expression of that right. Saying that self-defense is a right yet denying the right to carry a gun is like saying that free speech is a right while outlawing printing presses.
What of the Consequences?
Gun control advocates assert that it's necessary to control violent crime; gun-rights advocates assert that, as Robert Heinlein said, "an armed society is a polite society". Who's right? For years it was very hard to get good comparative data. The NRA would cite countries like Switzerland where gun ownership is mandatory and crimes are rare, while gun control organizations would cite locations where both gun ownership and crime were high, and so on. What we lacked was a controlled experiment in which two groups - identical in their cultural, historic, political and demographic makeup, but unalike in their gun ownership rates - were compared. We finally got that data when the shall issue movement took hold in the U.S., and literally overnight the laws changed and made gun carry much easier in state after state. As a result gun ownership and gun carry rates went way up in these states over the course of a couple years - too short a time for the population to change in any significant way. What happened? Crime went down.