> we all know that most if not all politicians are corrupt,
We do? Seems unnecessarily cynical. If that were true than by corollary most if not all people are corrupt, and that does not match my experience by far.
No one thinks their own frieds are corrupt. That's part of the corruption. The quiet benefeciaries "just following orders" and "useful idiots" of corruption aren't seen as corrupt.
Invalid logic. It is not necessary for most if not all people to be corrupt for the same to be true of politicians.
Many people are gullible.
Many people are easily manipulated.
This is especially true of those who are young, and prone to adopt the ideology of the group. But yes, I do believe that a significant portion of the population possess the brain anomaly that manifests as narcissism and these people are more successful than others at climbing political hierarchies because they are unrestrained by conscience.