Is there still a rational basis for the Second Amendment?

This post developed from an idle thought I had during a conversation with a friend, and as a result, is more of a meandering than anything else. But I thought it would be interesting to share here should it spark any interesting discussion. Quite simply: Is there still a rational and reasonable basis for the continued existence of the U.S. Constitution’s Second Amendment in this modern day and age? (Note: This post is about the Second Amendment specifically, not the right to bear arms in and of itself. More at the bottom of the post.)

I don’t pretend to be a legal or historical buff, so I’ll keep things simple. From what I do know, Amendment II’s raison d’être was generally bipartite:

1) Ensure national security through a well-armed militia to defend against invaders; and

2) Grant U.S. citizens the means to overthrow the federal government should it become tyrannical.

(I’m well aware that there’s more than enough detail and nuance with these points and others to sustain countless endless legal and historical debates, but for the purposes of this post, that was basically the basis for including the right to bear arms in the Bill of Rights.)

Both of these points were quite valid during the days when the Second Amendment was created and enacted. Tensions with then-imperialist Britain meant constant worry about being attacked, and one of the overarching themes throughout the Constitution and other writings from the Founding Fathers is a general concern for freedom from dominion one way or another (a natural reaction, considering how they’d recently warred for their independence). Allowing commoners to arm themselves and form militarized groups was an obvious and rational solution to the very real concerns of the time.

But that’s the thing: Times change. The fledgling and vulnerable United States during the ratification of the Bill of Rights bears little resemblance to its current form as a global superpower, and the centralized, well-equipped federal military that grew out of the Civil War renders both previous premises all but moot:

1) The risks of any U.S. territory (much less the mainland) being invaded by any external force beyond a rogue flock of seagulls is outright laughable in the age of rapid mobilization and nuclear arsenals (among many other factors); and

2) For essentially the same reason, nothing short of having every single American man, woman and child march into Washington, DC with rifles in hand would be sufficient to destabilize a government as broad and powerful as the United States’s, and given that even the revelations of the federal government’s extrajudicial surveillance, assassination and indefinite detainment programs couldn’t spur more than renewed pointless partisan chicanery, I have my doubts that the American population retains much interest in forcefully opposing their government’s possible tyranny.

In other words, for better or worse, the two key reasons why the Second Amendment was necessary in the first place simply don’t apply anymore with the might of the U.S. Military.

So then, what other evidentiary basis might there be for the lingering enshrinement of the U.S. citizenry’s right to bear arms in the U.S. Constitution? Or in other words, why shouldn’t it be repealed should the opportunity arise?

Note: My position on gun rights is that sensible control is best: Civilians should be allowed to purchase and own firearms so long as they submit to criminal and behavioral background checks to weed out as many undesirables as possible, followed by mandatory safety training and with obligatory checkups every few years or so. Assault rifles and other high-powered weapons one would expect to see on a military battlefield should be restricted, as I can’t see a good reason why any random schmuck would need to walk around toting an AR-15 for “self-defense”. As for limits of gun and ammo quantities, that’s another tangent I’m not interested in broaching at the moment.

If anything, repealing the Second Amendment might be worth it just to put an end to the fetishism it’s subjected to from the rabidly pro-gun lobby.