well, i think it's worth noting that, from a historical standpoint, no economic or political system has ever "worked" indefinitely. the founding fathers' principles are still largely in place as viewed through a modern lens. the difference now is not as much difference in laws as it is in people and their lifestyles and choices, IMO.
america's been successful in a lot of ways, but just like everyone else, we've got some major skeletons in the closet (an apt idiom for this forum
) that we really haven't been come to terms with (case in point: the hyper-nationalistic attitude that "america is #1 and don't you dare speak a word against it"). this is the same kind of thing that's been happening here in the US for many years now, it's not really a recent shift. in fact, this is pretty watered down compared to the atrocities that have been happening here for the last 300-odd years.
i guess i just don't really get the shock and disbelief at its occurrence. yeah, it's horrible shit. but you ought not be surprised that it's happening in america -- brutality is as much a part of our legacy as is landing on the moon and stopping hitler.