You are ignoring those folks who would have failed the test but have NOT gone postal.........
Would probably be a good idea to read through the thread. I'm not ignoring them. I've stipulated what my inputs would be. One example I've used consistently here is schizophrenia. I personally don't want that guy that sits out in front of the local quick mart while talking, yelling, and making crazy gestures off into space to have the right to buy a gun. Currently, he does have that right if he hasn't gone postal to this point. But, he doesn't have the capacity to properly own one.
No one fails the test! It is an inventory of personality traits. If
everyone agrees that certain personality traits or sets of personality traits that are well-defined, scientifically known and are generally agreed upon to be precursors to undesirable behavior, then the "red flag" goes up and that person is precluded, or is said to lack the legal capacity to responsibly own and manage a firearm. Another example of legal capacity would be a three year old child. It's generally agreed that a three year old lacks the legal capacity to own and operate a firearm. Most states have age limitations for the purchase of a firearm. States would say a 3 y.o. has no legal capacity to purchase and own a gun, yet the 2A has no provision for this. Now, there are also low-functioning adults that could be said to function at a 3 year olds understanding of the world. Should this adult be precluded from 2A rights?
IMO, it is safe to say that someone who can bring themself to shoot a bunch of people without cause would also be willing to buy a firearm illegally..
This argument has already been presented (ad nauseum) and discussed. It is one of Mr. Leary's (the OP) original points. How are all these illegal guns entering that clandestine market when so many here want to portray gun owners as being responsible? Who are these "responsible gun owners" that lost control of their firearms? The reason is simple, every manner of idiot can by a gun. Many of these idiots didn't have to take a class in proper gun safety and storage. Many of these idiots shouldn't have 2A rights. But, how do we discern these idiots from the rest of us. We'd know who the idiots are if they couldn't pass a simple written test on those subjects. Assuming some of the idiots were to pass, at least we would have had their attention for half a day to engrain them with some good safety information and maybe, just maybe...a sense of responsibility. That same sense of responsibilty might help limit the number of guns that slip into the dark side.
To honestly answer your question (and I see where you are going with this) I don't know. My best answer would be too only exclude those who have shown themselves to be dangerous. You can't discriminate on what someone "might" do..
Sure you can. Would you mind if your state arbitrarily decided to began allowing auto sales and offering drivers licenses to the blind, mentally retarded, clinical insane, or ten year olds "who haven't shown themselves to be dangerous"?
These people do not have legal capacity for such things because it has been wisely determined that it would not be safe. Allowing gun ownership to these same people would also be unsafe.
It may take some doing to kill a room full of people with a single shot .410, but it is pretty easy to kill a room full of people with a can of gas and a chain......just saying.
Dooooood, seriously. Again, asked and answered counselor.
What if a guy backs his car to the house and runs a hose from his exhaust into one of the windows?
What's to keep a guy from using a chain saw from Home Depot?
What about a guy that uses a pair of pliers to ....?
What's to keep a guy from throwing banana peels in front of old people?
Do you see where this goes? Crap, the sad thing is these things have probably all been done. But, as Mr. Leary has already pointed out, overwhelmingly, these aren't the methods of choice for "going postal".
I don't think anyone is advocating doing nothing.
Actually, several people in this thread have advocated precisely that. Many who haven't been quite that closed-minded, but still lean in that direction continue to drop the same arguments. Some will think they're being clever by rephrasing the same point and then regurgitating it, but it's still the same tired re-hash. Maybe the thread has reached the point where people have gotten to lazy to read it through.