The Founders could never have imagined “assault weapons.”

Yes, yes, because James Madison, who wrote the Bill of Rights (with input from plenty of others, but he’s the one who set quill to parchment for the final wording) was still alive when the revolver was invented.  Why I’ve got his note right here that says “these deadly repeating pistols, why a person could easily carry four or five of them on his person ready to use giving a single individual enough firepower to kill thirty people in as many seconds.  The Second Amendment was never intended to protect such wanton engines of destruction.”

No?  What’s that?  He wrote no such thing?

Hmm.  How about the Congressional debates over “Richard Gatling and his horrid engine of war that spits out dozens of bullets every second just by turning a crank” and whether it was protected by the Second?  No?  No such debates?

Well then how about “Hiram Maxim has developed this destructive device that one doesn’t even have to crank!  Just depress the trigger and it will keep firing until it runs out of ammunition.” Surely there were debates over whether it was legal or covered by the Second Amendment.  No?  There weren’t?

Well, then, how about “John Browning has developed a firearm that can be fired as fast as one can pull the trigger, holds more than most revolvers, and can be reloaded in less than two seconds.  This kind of weapon was never intended to be protected by the 2nd Amendment.” Surely the courts and Congress in 1912 or so addressed that issue.  No?  They didn’t?

Seriously, the idea that a group of founders that included folk like Benjamin Franklin (one of those present at the Constitutional Convention) and Thomas Jefferson (not present but a strong voice of influence) could not imagine weapon technology improving, even if they did not envision the specific directions, is beyond ludicrous.  If they’d intended to limit the 2nd to the technology of the 1780’s, they could, and would, have said so.

Indeed, it took until the Miller case in 1939 for the idea that some weapons might not be “covered” by the Second Amendment to be addressed by the courts.  In the Miller case, Miller had died before the case came to the Supreme Court.  Only the government’s side was heard.  And the court still didn’t rule unequivocally in the government’s favor.  Instead, they noted that they did not have “judicial notice” that the specific weapon, a short barreled shotgun (“sawed off” in common parlance, but it’s the barrel length and overall length that were the legal issues whether sawed to get that way or not), was an appropriate weapon for military use (nobody had told them that “trench sweepers” were a common weapon in WWI) and remanded the case back down to lower for review on that basis and there it died because, well, Miller was dead and there was no one left to pursue the matter.

People have since cited Miller saying “See, you have to be in a militia” when actually it only addressed whether the weapons was useful to a militia.

The idea that the 2nd only applies to the arms at the time of the writing of the Constitution is a new one, invented by people who don’t like the idea that people have firearms at all. (Don’t think so?  Get one of them to go so far as to support repealing “gun free zones” so long as the “gun” in question is a flintlock muzzleloader or permitting “constitutional carry” of same.)

And, frankly, the Supreme Court agrees:

Some have made the argument, bordering on the frivolous, that only those arms in existence in the 18th century are protected by the Second Amendment. We do not interpret constitutional rights that way. Just as the First Amendment protects modern forms of communications, e.g., Reno v. American Civil Liberties Union, 521 U. S. 844, 849 (1997), and the Fourth Amendment applies to modern forms of search, e.g., Kyllo v. United States, 533 U. S. 27, 35–36 (2001), the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding.

Now, one can make the argument that there are weapons that should not be covered under the 2nd (nuclear and bio come to mind), but there’s a solution to that, and one found within the Constitution itself.  The people who wrote the Constitution understood that it would have to adapt to changing circumstances.  That’s why they put in the Amendment process.

If you want to change the 2nd to accommodate changes in weapons technology, then do so, but do it right:  amend. the. Constitution.  Get 2/3 of the Senate and 2/3 of the House to agree to a proposed Amendment, then get 3/4 of the States to sign off on it.

That’s what the Amendment process is there for.

But just deciding that it means something other than both its plain words and the intent of the folk who wrote it (as found in their writings at the time) is to make the Constitution meaningless. because if they can “redefine” that, then they can redefine anything.