There is a book called Political Ponerology, with a fascinating provenance, which basically claims society at large (macro scale) goes on sawtooth pattern like this. The argument is that during the good times, people stop taking the steps needed to keep these people from attaining high positions... they remain in denial and make excuses for pyscho behavior. Then people finally take action only when it's just blatantly obviously necessary again. Which, if you think about it, is also the basic story of good & evil presented in Harry Potter :)

IIRC the book was written by the scientific wing of the Polish Resistance movement during authoritarian occupations of the 20th Century. Apparently, many of the people involved in sourcing the data (and, oh yeah, who had secretly diagnosed many of the Nazi/Communist leaders as psychopaths) were killed, when the first edition of the book was discovered in progress. And that first manuscript was destroyed, but the lead author wrote it again -- not once, but two more times -- and ultimately, had to wait for the fall of Communism in order to get it out of Poland. It was finally translated and published during the Bush administration, by New York liberals.