I've been following the over-politicization of the Tucson shooting, from the Daily Show, the NY Times, and a few snippets from both the left and right wing of America's struggling mascot: the Bald Eagle (if only they would realize that you can't fly with only one wing, we'd be far better off). There seem to be two camps, as far as I can tell; one side wants fewer guns in the hands of fewer citizens, the other wants more guns in the hands of more citizens.
Those who are lobbying for more guns, in more places, for more people, seem to think that disputes that among people who are all equally armed end up like a mini Cold War. I've personally been in a few of these sorts of disputes, and I've found that adding additional guns never seems to result in less violence. The person diffusing the situation is generally unarmed, and doing so with conversation. Granted, this method doesn't always work, but it does seem to have a higher likelihood of succeeding than simply pulling out another gun.
The other argument for more guns is that violent, armed combatants are less likely to engage a victim if said victim is more likely to be "packing heat", or if the nearby citizenry resemble disgruntled postal vigilantes with a hair-trigger and "more straps than a jansport". This line of thinking is problematic for a couple reasons. The first is that we have examples of areas infused with weaponry, like most american cities, and a study done recently by the University of Pennsylvania on the outcome of gun-toting victims in armed encounters found "that people with a gun were 4.5 times more likely to be shot in an assault than those not possessing a gun." I've been mugged, at gunpoint. It sucks, but at no point in that encounter would my having a gun done anything but exacerbate the situation.
The second problem is not always precisely obvious to most people, and is something you only discover if you are actually faced with a situation in which shooting becomes a plausible solution. Real fights, involving really angry people with really loaded guns, are chaotic and messy. Nothing goes the way you think it will; the first few seconds, especially, are completely bewildering your first time at bat. Even in situations where you know a certain person is the bad guy, he/she is rarely standing 25 yards away, alone, with a 12ft berm in the background. Anyone unfamiliar with CQC protocols and safety measures, detailed ballistics information, foreknowledge of the target and kill-zone, and solid ID and loc on all friendly positions runs a massively irresponsible risk when discharging a firearm. Even highly trained, experienced trigger men and women make catastrophic mistakes in these situations. This naive idea that the average joe is going to pull a quick and clean Dirty Harry on some unsuspecting mugger, or that some bystander is going to jump in like Batman in the alleys of Gotham is ludicrous, and far more dangerous than simply losing a couple bucks and a wallet you got for christmas.
The alternative, i.e. fewer guns for fewer people, in fewer places, runs up against a very simple constitutional problem. The second amendment wasn't written for short sleeve shirts, it is a clear license for the citizenry to own guns, if they so choose. However, there is no written clause or rule in the constitution that says you can carry said weapon into the grocery store or a government building. Have your guns, but have them at home.