I don't wholly agree with this. When the person at the top who comes to power is somebody very intent on giving a "bad example" in every sense, he somehow seems to give license to all those who were kept in reigns until now by conventions, political correctness, call it how you want, to break out the worst in them.
I have seen it happen in Italy.. when Berlusconi came to power, the "dark side" in every Italian - the cheating, macho, primitive part - finally saw a possibility to express itself, and express itself it did. The general social climate has gotten so much worse in those years, the country has not been the same and probably will never be again. Something is broken, obviously it is not "only" Berlusconi's fault, but he caught the collective subconscious' worst parts and made them into a physical form. Just like Hitler did with the Germans, and and and....