The Purpose of the Second Amendment Failed Long Since

The American colonies and the new United States were deeply distrustful of a standing army, a distrust inherited from their English Whig forebears. That is why the army and the navy were treated so differently in the Constitution.

Congress has the Article I, Section 8 power to “provide and maintain a Navy.” But its powers with respect to an army are severely constrained: “To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years” There was not to be a maintained army, but only armies to be raised and supported as needed, subject to the two year limitation on any appropriation for such armies.

In the absence of a standing army, there needed to be some means of quick response in the event of insurrection or unexpected land invasion, say from Canada or Florida. That assignment fell to the militia, as set out in section 8 immediately after the navy and armies provisions.

To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;

To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;

There was a widespread fear, engendered by the Confederation period, that tax cutters in the states might stint on weapons and training for the militia. Hence the Section 8 specification of a federal role.It was necessary that the militia be equipped and ready. Disaster might ensue before a federal army could be raised by Congress.
 
Virginia's proposed version of what became the Second Amendment made explicit the connection between the right to keep and bear arms, the distrust of standing armies, and the role of the militia:
 

That the people have a right to keep and bear arms; that a well regulated Militia composed of the body of the people trained to arms is the proper , natural and safe defence of a free State. That standing armies in time of peace are dangerous to liberty, and therefore ought to be avoided as far as the circumstances and protection of the Community will admit, ...

New Hampshire went so far as to propose a ¾ vote of each house of congress before a standing army could be instituted.

That its purpose was to insure that the militia would be adequately equipped with weapons was included in the language of Madison's original draft of the Second Amendment:

The right of the people to keep and bear arms shall not be infringed; a well armed and well regulated militia being the best security of a free country, but no person religiously scrupulous of bearing arms shall be compelled to render military service in person.

There is no evidence whatsoever that the removal of “well armed” was thought by anyone to be substantive. It was apparently a merely stylistic compression. Everyone knew that a well armed as well as well regulated militia was the point of the amendment. Moving the militia clause to the front of the amendment, in Congress's final version, reinforced the underlying purpose of the amendment:

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed. 

 

The key historical fact is that the founding generation, or most of it, thought a free state and a standing army were incompatible. To provide security against insurrection and surprise aggression by land, therefore, a well regulated militia was necessary, and people should have a right to keep and bear arms just in case the states and the Congress had not otherwise provided adequate weaponry for the militia.

So the Second Amendment was part and parcel of the constitutional devices to make a standing army unnecessary (and, at best, difficult). In this the amendment failed of its purpose completely and failed from very early on. Perhaps a case of fine grained historical detail could be made that there was no real standing army in some early years, but it is at least roughly fair to say that a standing army has been with us always.

(The prestige of the militias took a sharp dive during the War of 1812, and with that the need for a standing army became more widely accepted.)

It is ironic that the loudest Constitution-thumpers among politicians, who declaim their favorite quotes from the framers at the drop of a hat, are among the most lavish in their support of what makes the United States Army more robustly standing than any army ever seen on the face of the earth. 
 
The history also, of course, shows how ludicrous is the insurrectionary theory of the Second Amendment: that there is a constitutional right to arms in order that the people may overthrow a tyrannical government. Once the property only of fringe cults, the insurrectionary theory has gained prominence since its adoption by the NRA leadership. Recently Senator Ted Cruz stated that the amendment exists as "a fundamental check on government."  An amendment that was in fact put in place to insure the quick putting down of insurrection is now trumpeted as the guaranty of a right to insurrection!

Purposes as shown by history, and even those purposes that appear on the face of document, are not, however, the last word in constitutional construction. On better interpretations than the NRA or either the majority or minority of the Supreme Court have given it, the Second Amendment would have continuing force, even though its motivating purpose failed, and its instrumental purpose in the adequate arming of the militia became otiose. Some remarks on that better construction in a later post. 

See: "The Second Amendment: Not One or Two but Three Rights," http://lawrencecrocker.blogspot.com/2016/07/the-second-amendment-not-one-or-two-but.html;  "The 2nd Amendment Right to the Open Carry of Swords and Shoulder Launched Missiles," https://lawrencecrocker.blogspot.com/2016/04/the-2nd-amendment-right-to-open-carry.html. “Guns don’t kill people, true – in exactly the same way ricin and hand grenades don’t kill people,”   https://lawrencecrocker.blogspot.com/2019/09/guns-dont-kill-people-true-in-exactly.html.