There is a great book called Political Ponerology
It explains in detail how a society is lulled to sleep during the prosperous and good times and how the psychopaths gain footholds in the power centers of the society. While the people are drunk on peace and prosperity, the psychopaths climb the ranks. About 5% of the population are born psychopaths. Others acquire the tendencies from the psychopaths as it becomes increasingly acceptable once the true psychopaths are in power.
So, this sort of system is cyclical in a society, according to what I gathered from the book. Averting being captured by psychopaths requires vigilance and resistance from a society - something that is difficult in a generation that has not suffered such a fate during their lifetime.