"Capitalism" doesn't decay into cronyism by itself. Government interference in the economy distorts capitalism into cronyism. Socialism doesn't decay into communism, because one is an economic system and one is a political system. It's not that power corrupts -- it's that the power itself is a violation of natural rights. I own myself, and I own my rightfully-acquired property. Government does not have a superior claim to my body or my property. The institution of government itself IS the corruption. Politicians and bureaucrats cannot be prevented from corrupting government because it is corrupt by definition. The types of people attracted to positions in government are those who enjoy the exercise of power; specifically, the power to violate the rights of others. We do not need constant vigilance if we simply remove the problem. The problem is statism, and this worship of government. Statism is the most destructive religion there is, and it's taught to people practically from birth.