We are not nearly as evolved as we think we are:
The history of all hitherto existing society is the history of class struggles. Freeman and slave, patrician and plebeian, lord and serf, guild-master and journeyman, in a word, oppressor and oppressed, stood in constant opposition to one another, carried on an uninterrupted, now hidden, now open fight, a fight that each time ended, either in a revolutionary re-constitution of society at large, or in the common ruin of the contending classes.
It is plainly evident that Marx was extremely accurate in his assessment of the natural social order that will emerge if left to its own development. We have numerous examples of this in the 21st Century, nearly all of them the result of failed states. Neo-feudalism is actually the best they can hope for, and that is something everybody needs to keep in mind when discussing "revolution" and the redesign of American society. Marx was right, but as scientists will tell you identifying a problem is worlds away from solving said problem. Conflict of this sort is ancient; it was (is) not the result of a particular form of government, or economic system, or ideological bent. It is primal, and cannot be eradicated through violence: