Oh the reason why the left wants you disarmed is very simple - it's more to do with the idea of individuals fending for themselves, at least in terms of self-defence. In case you hadn't noticed, the left wingers are ALWAYS against people fending for themselves, unless of course they're rich and white and been taxed to death.
One sniper was able to spread terror among innocent civilians. It is hard to imagine that paradigm working in relation to the government.
Regards, Ivan