The 2nd Amendment is defence policy. The people who wrote it were attempting to ensure that the defence of the United States would remain in the hands of civilian militias, due to their distrust of standing armies. That didn't happen. The federal government quickly realised that a standing army would be much more effective at fighting the natives during the westward expansion. In the following centuries, the face of warfare changed significantly. We are now in the era of combined arms warfare, with artillery arguably being the star. The circumstances under which the 2nd Amendment was written are long gone. It is now publicly championed by people wish to use firearms as personal protection, or as a means to fight the federal government. Privately, it is beloved by those with extreme ideologies which encourage them to perform acts of violence.