That is, organized, disciplined, well-supplied, trained and professionally-led troops commissioned by state legislatures. The founders did not like the idea of standing peacetime national armies (they saw them as a tool of tyrants) but they were well aware the individual states needed bayonets to maintain public order, put down rebellions, protect against Indian attack, and (of course) crush slave revolts. And the founders saw militias as a means of defending against overreaching federal power.

"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 2nd amendment has absolutely nothing to do with the private ownership of firearms, it has to do with the authorization of state militias. After all, in the 18th century, on the frontier or on the farm, a musket or rifle was just agricultural equipment which "gentlemen of property" could easily afford. Needless to say, flintlock muzzle loaders weren't very practical in either committing or defending against street crime. Pistols were primarily for dueling. Muskets and rifles were bulky, and even pistols were not robust enough to be easily portable. The exposed firing pan and lock were delicate mechanisms and powder and flint could easily absorb moisture from the atmosphere. They were meant to be loaded just prior to use.

Besides, if you weren't a white man AND a "Gentleman Of Property" you weren't even allowed to vote. You were just a worker who probably couldn't afford a firearm. You might even not be able to afford a knife. The G.O.P. could always pack a sword.

Of course, the gun lobby is perfectly aware of all this. They just have interpreted the Constitution to suit their own political purposes: to pander to their brutish and paranoid partisans and to subsidize an industry which is always on the verge of saturating its market. Remember, guns are very durable products. If well maintained they can last for generations. To sell more of them you have to sell the idea of multiple firearms of multiple configuration for multiple applications. You also have to justify their ownership as essential for personal survival against Commie paratroops and/or hordes of similarly armed villains.

And that, my friends, is a self-fulfilling prophecy.