In the Western Tradition we have done away with executing all but the most egregious failed politicians. Unfortunately, that just encourages more.
I think I have an explanation, if not a solution. We are confronted with what may be called the Leadership Paradox. That is the concept that in our age, those most unworthy and undeserving to hold power and influence over others often are the most effective and energetic at seeking and obtaining that power.
That may go part-in-parcel with another principle which may be called the Prosperity Paradox, which is the concept that prolonged, increased general prosperity tends over time to erode and neutralize the conditions which produced that prosperity in the first place.
The invention of the mass media (television, Internet) created a force which tends to enable cacogenic (degenerate) influences and persons because the nature of mass media is that those with skill at manipulating and promulgating illusions are likely to succeed far better than those who are simply moral, competent and self disciplined in administration and communication.
When words have grater power as munitions (the effect that they create) than as tools to exchange thoughts, opinions and ideas that is a dynamic which probably favors pathological personality types more so than healthier personality types.
Which leads us back again to the Leadership Paradox.