The need for guns really is caused by the guns themselves. You can't randomly take them away from someone without taking them away from everyone including the government. (The UK figured that out at least.) Mexican standoff, really. Until such law passes, I think you need a gun just to protect yourself from the reams of idiots having them. I'm not against them for that reason, but if they could all be taken away at the same time -- that's what I'd support.
My argument against normal citizens having guns is simply along the lines of having no confidence in their decision making ability. Much like you won't hand a gun to a toddler, lol. The people who are the most ardent of gun supporter as also the fundamentalists, and lowest educated in the USA. People who see things in absolute right and wrong or in other binary ways have no business with guns, nor do the intellectually challenged. You should be tested, and if you don't show up with normal psychology or normal thinking then no gun. You should have to visit a psychologist/psychiatrist to even purchase one, and have to have the permission in hand. Am I being ridiculous? When the penalty for screwing this up is: "Someone dies", then I think we need to take this to a whole new level of evaluation.