One more set of comments and then I'm getting off of the Giffords thing. Palin and Glenn Reynolds and the torrential flow of stupid is making my head hurt. Like yesterday, I have two separate but related points. Unfortunately (for me) a lot of writers around the internets have already jumped on these, but I'll say my peace anyway.

So let's talk about the 800 pound gorilla in the political aftermath of America's semimonthly mass shootings. Let's talk about guns.

1. This is not a photo of the actual weapon used in the shooting on Saturday, but it is the same caliber and with the same magazine:

Since the Assault Weapon ban was allowed to die in 2004, cheap, high capacity "extended" magazines have flooded the market. They are illegal in a handful of states but easily available online, at gun shows, and so on. No one who identifies as a strong pro-gun advocate has ever been able to offer a remotely convincing (or even plausible) answer to my question regarding the above photo: what legitimate purpose can this possibly serve?

Recreation? I'm pretty sure you can recreate with the standard 15 round magazine. Hunting? Who in the hell hunts with a pistol? And if you did, do you need 33 rounds in case the deer call for backup? Personal defense? Well, that looks very difficult to conceal and remarkably awkward to handle, aim, and fire under duress – and once again, only in the most sophomoric Rambo fantasies can anyone concoct a scenario in which you would need to shoot 33 times at a mugger or home invader. The gun pictured above was basically designed around the firearm needs of Mexican drug cartels.

This is an example of what's wrong with gun politics, and the NRA in particular, in this country. Americans, including Ed, have no problem whatsoever with the fundamental right to own a firearm. But the NRA has been insisting for 30 years (Does anyone even realize that they used to be sane?) that Americans are guaranteed the right to own every and any type of firearm their hearts desire. This is patently false, unsupported by anything in the Constitution or laws that followed it. Armor-piercing bullets! .50 cal anti-materiel rifles! Full automatic! 35 round magazines! Hand grenades! You can't ban anything because it will be a slippery slope to banning everything!

Let's be clear: the 33 round magazine for a 9mm handgun – like the one pictured here and used in the Giffords shooting – serves absolutely no purpose whatsoever except to enhance the number of rounds that can be fired in a spree killing or drive-by shooting. On the off chance that Congress considers a knee-jerk ban on these magazines it won't matter, as tens of thousands of them already circulate in the U.S. And capacity is certainly not the only relevant factor, as the Virginia Tech shooter used handguns with standard 10- and 15-round magazines (although even the 15 was banned until 2004). What this is, however, is an excellent example of how the "Guns don't kill people" argument is deeply flawed. With 15 rounds, the Tucson shooter hits (and possibly kills) half as many people. Our insanely lenient gun laws directly resulted in him being a better and more productive killer. We have ensured that when people snap and decide to start shooting people, they can shoot more, and more powerful, ammunition.

2. Fox News is furiously pounding away at its collective pud over the non-story of the innocent bystander who was armed and rushed over to confront the shooter – the typical right-wing "saves the day with his concealed handgun" fantasy. Alas, the assailant had already been subdued by (unarmed) bystanders when Johnny Rambo arrived. What the WSJ story that started this meme neglects to mention is pretty stunning:

"I came out of that store, I clicked the safety off, and I was ready," he explained on Fox and Friends. "I had my hand on my gun. I had it in my jacket pocket here. And I came around the corner like this." Zamudio demonstrated how his shooting hand was wrapped around the weapon, poised to draw and fire. As he rounded the corner, he saw a man holding a gun. "And that's who I at first thought was the shooter," Zamudio recalled. "I told him to 'Drop it, drop it!' "

But the man with the gun wasn't the shooter. He had wrested the gun away from the shooter. "Had you shot that guy, it would have been a big, fat mess," the interviewer pointed out.

Zamudio agreed. "I was very lucky. Honestly, it was a matter of seconds. Two, maybe three seconds between when I came through the doorway and when I was laying on top of [the real shooter], holding him down. So, I mean, in that short amount of time I made a lot of really big decisions really fast. … I was really lucky."

When Zamudio was asked what kind of weapons training he'd had, he answered: "My father raised me around guns … so I'm really comfortable with them. But I've never been in the military or had any professional training. I just reacted."

In other words, the effect of Zamudio's weapon in this incident was to dramatically increase the odds that someone else who had nothing to do with the attack was shot and perhaps killed. Among right wingers, the "saves the day with guns" fantasy has cured more unresponsive penises throughout the years than all of the Viagra in the world. While it's commendable that he (and other unarmed bystanders) intervened, Zamudio is the prototype of the self-certified, self-trained, self-appointed vigilante who dreams of blazing away at the bad guys but in reality can only produce one of three outcomes:

1. Vigilante shoots the assailant. Victory parades are held in his honor.
2. Vigilante shoots additional victims, either through poor aim or mistaken identity.
3. Vigilante is shot by the real cops who arrive to find some idiot in street clothes blazing away like John Woo is directing him.

One of those three is a positive outcome, and it is arguably the least likely one by far. Just as guns kept in the home for "defense" are infinitely more likely to be used in a suicide, homicide, or firearm-related accident than to be used against actual Bad Guys, introducing more armed people into spree shooting scenarios offers poor odds of making the situation much better along with much higher odds that the situation will be made worse.

It's a great Prospect Theory problem if ever there was one.