"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 problem with the Constitution is that a priesthood took it over about two hundred years ago. That order comes in two flavors, red & blue. While many on both sides of the 'guns' issue will have a field day of discontent and celebration, any cause for such has long been lost in a ghastly display of reason based on hierarchy and plain old power. 
Seems to me that the average folk throughout the ages can easily interpret the second amendment as simply " Well, we had to take up arms against Britain, you never know. So let's not abridge the right to do so." That's now called 'originalism' (though its doubtful that any current justice in that camp would deign to come down to such prosaic and simple language or justification, they still have to hang out together), and while its often rendered quaint by the devious and cunning brutes who feel their relationship to power entitles them to decree, it has become the last weak stand by those who counter the blue players on the board near check mate time.
The scary part of all this was the idea that gun ownership wasn't an individual right all along. While it wasn't often ruled on, the forces of regulation, control and what some might consider victim disarmament, were willing to try this tact in order to make an end run on the originalists.
To be sure, the regulators are classic control freaks who would monitor every aspect of the collective in order to assure the possibility of the odd middle class, of the road and the political spectrum, some sort of milquetoast happiness of security based on SAT scores and home square footage. But the reality is that Americans like their guns and don't want them taken away by the robed eggheads that constitute this modern priesthood.
That priesthood left plenty of totalitarian wiggle room too. Rather than affirm the general principle, "being necessary to the security of a free State", they ran hard away from opening up Pandora's box of gun deregulation and suits. Yep, it will all stay nice and comfortable. A couple times a decade they'll lift their robes to feed the 'rights' urchins their tasty morsels of wisdom.
'Good' citizens, not criminals or the mentally ill, will have ample opportunity to fill out paperwork, get background checked, register their firearms and take mandated courses of gun ownership from a group that exists as a powerful lobby in Washington. In my county I have to take the NRA course in order to own a gun. I object to this because their affiliate in NY won't even consider 'rating', let alone endorsing, Libertarian Party candidates.
Even though this decision was an affirmation of some ultimate principle (albeit temporarily if the red ever controls an appointment or two), it's still at the altar of those who would pray to an old document in front of the people and meanwhile back at the Vatican they decide all the popes, cardinals, bishopric(k)s, and priests. Just for a minute try to envision a court with justices from the Green or Libertarian Party. I'm sure their Constitution would look vastly different.
I can't even fathom such a critter as a "collective right". If no individual has a right to do it (such as steal), then no group of individuals have the right to do it (such as "tax"). Each and every one of us, as individuals, have an absolute right to own and to carry, everywhere we go, whatever kind of weapon we wish in any way we see fit without asking permission from anyone, ESPECIALLY the aggressors who wish to abuse us. Those aggressors include the psychos of the "Supreme (cross dressing, furniture abusing) Court".
Kent - Your line of reasoning may bring property rights to bear into the discussion. Don't I have a right to ask you not to bring arms onto my property (you certainly have a right to decline entry . . . but does your right to protect yourself extend into my domain?)? Thus similar logic could be utilized in terms of 'public' property and the rights of those owners (the members of that society) to ask the same thing. While this opens up another round of what can democracy justify, the logic that follows is sound. Perhaps not just or ultimately morally acceptable, but it follows from the premise.
I was wondering what your response to this case would be. I'm reading Crispin Sartwell's 'Against the State' and he deals with a lot of these questions.