Andrew Sullivan points to a comment by Stephen Pinker who wonders if high homicide rates in the US are a consequence of a different type of implicit social contract here due to the peculiar nature of the nation;s establishment:
My own guess is that Americans (particularly in the south and west) never really signed on to a social contract that gave government a monopoly on the legitimate use of violence, as Europe did. Americans not only retain the right to bear arms but believe it is their responsibility, not the government’s, to deter harm-doers. With private citizens, flush with self-serving biases, acting as judge, jury, and executioner, body counts can pile up as trigger-happy vigilantes mete out rough justice. This may be a legacy of the long periods of anarchy in the mountainous south and frontier west, and of the historical failure of the police and courts to serve African American communities.
This put a twist on our earlier discussion of the Declaration of Independence and Locke's arguments in general. Did the signers of the declaration speak for all Americans? As American moved west, there was no authority in place to consent to, this followed expansion.