You just nailed it with this statement mate. In most society their is always a group of powerful corrupt people that protect themselves from any of them facing the full wrath of the law. In my country godatherism is the main problem why corruption will be difficult to stop, because an out going governor, a political or economic leader will do everything to put his boy there, so that all his shit will not be exposed, and brought to book, that is why you will hardly see a politician goes to prison upon the terrible things he did while in office. So I utterly agree with you when you said that something a whole group of powerful people keeps on protecting themselves, and since they are powerful, most people will be afraid of crossing any of them, which I believe is in every community worldwide.
You can find corrupt leaders in all the countries especially in the government. And what they do to remain powerful is maintaining their secrets and then they will pass it to their successor who then will hide their secrets and carry on with their legacy. This is because if there secrets is exposed it can bring down their empires. So that is why they anoint a trusted person as their successor that will protect what they have builds over the years. Sometimes their successor may not like to follow the same path like their godfathers and that will cause a great misunderstanding. In some countries,citizens protest against godfatherism,some of them gets killed during the protests by security forces who might be following orders from above and that's bad.
I have been in politics before, and I can tell you, they do not allow people who are not corrupt to go further; that is the reason. Well, if a person is corrupt already and at the top, then they want corrupt people around them. If you are not corrupt, you will not be around them. This is true for a president; this is true for a mayor of a small village, doesn't matter.
So if you are not corrupt and want to get into politics, you can do it independently if you want, and in that case you will have a very low chance of getting elected in today's world where everyone is "my team and other team", where you are not even in any team. Or you will pick a team, and corrupt people of that party will not let you grow into a bigger position; they won't appoint you, and all you have is being nominated, and usually nominations even go through that party, and if not, they will support the corrupt one more, and you will lose. Very rarely do people get any power if they are not corrupt.