An anthropological view - Moral failings of leaders collapsed even the best societies, finds study
"In a good governance society, a moral leader is one who upholds the core principles and ethos and creeds and values of the overall society," related Feinman. "Most societies have some kind of social contract, whether that's written out or not, and if you have a leader who breaks those principles, then people lose trust, diminish their willingness to pay taxes, move away, or take other steps that undercut the fiscal health of the polity."
Apparently Arnold Toynbee saw this trend as well.
3 Do not put your trust in princes,
in mortal men, who cannot save.
4 When their spirit departs, they return to the ground;
on that very day their plans come to nothing.
5 Blessed is he whose help is the God of Jacob,
whose hope is in the LORD his God,
6 the Maker of heaven and earth,
the sea, and everything in them–
the LORD, who remains faithful forever.
7 He upholds the cause of the oppressed
and gives food to the hungry.
The LORD sets prisoners free,
8 the LORD gives sight to the blind,
the LORD lifts up those who are bowed down,
the LORD loves the righteous.
9 The LORD watches over the alien
and sustains the fatherless and the widow,
but he frustrates the ways of the wicked.(Psalm146:3-9)