One needs to understand the historical context of the Second Amendment.  In a time when firearms were crude and militias, raised from the residents of an area, were the primary means of defence, the right to bear arms made sense.  This is no longer the case.  The US faces no existential threats, except possibly from itself.

There is a paranoia of government and of "strangers" that runs deep in the American psyche.  Americans feel this need for high-powered self-protection.  Groups such as the NRA feed this shamelessly for their ends, to be sure, but they are not the source of the problem.