A good leader of a nation is the exception not the rule.
Power does not favor clean people, or rather gaining power is much easier for people that can engage in morally questionable and immoral tactics.
The real point of democracy is not the rule of the people, but rather setting the rules so that those that seek power will seek votes rather than kill the opposition to rule. Further more the system of democracy will always tend to create a musical chairs environment where no single group ends up with power long enough to monopolize it. Regretfully sooner or later that will happen and democracy will degenerate. The most therefore that can be hoped from democracy is to vent the energies of the corrupt in such a way that the normal people have a chance at living a decent and somewhat comfortable life.
Every great and moral society will descend into bloodshed if resources are scarce enough that not all of the people will survive on them. Civilization is built upon excess of resources, people that do not see that are usually the first to die in the shortage of resources. People fighting to live are not evil, the evil are the people that live in excess that still fight not to survive but to have more.
Technology ( Think printing press, not just computers ) has empowered the people in fighting the oppression of the ruling few. This is not guaranteed though. As technology gets more sophisticated and powerful only the high IQ will be able to use it effectively and a new feudal system could kill all democracies, its signs are starting to show in government programs that spy on their own populations and huge portals like Facebook that have total history including location of billions of people.
Every one is blind to his own faults, no exceptions. Some of us are more blind than others though and some of us love faults.
Evil is real, and if you can not find it in your self, then as above you are blind to your own faults.
Life is not fair, get over it.
Justice is an ideal, never realized. But if we stop trying to realize it, if we stop putting an effort, then the civil society and democracy breaks apart fast.
It is easy to fool people. It is harder for people to realize that they have been fooled once they have been fooled until it is too late.
stupidity is contagious. For an example look up mass hysteria.
Logic sometimes fails. Saying that there is no love is wrong, saying that love exists is also wrong. Logic has failed in even defining love, let alone understand it. Feelings are of a different realm.
Trying to prove or disprove the existence of God by logic is stupidity itself, by very definition of most believers in God, he is above nature and thus above understanding. All you need to know the magic that God put in you is to close the door and lights in a dark room, free yourself of worry, and breath deeply. If you feel that you are a biological construct governed totally by the forces of nature, that your brain and thus thoughts and consciousness is a product of only the biological computer that is your brain, if feelings only register as red warning lights on a car dashboard, then congratulations you are a robot. If however you feel that you are a human with a free will that is limited by your physical presence but does not define it, then you have taken the first steps to understanding that you have a soul and that there is a deeper existence than that offered by the vision of scientists who only deal in the measurable and visible and totally disregard the spiritual.