World fundamentals are that criminals run the world and rule the world.
Nobody can't reach high level on goverment If she or he not criminal in mind to steal lia cheat scam.
World stands on honest people efforts and work labour. Goverments respect criminals If you are ready to scam and do bad things world society respect you specially the goverment officials every criminal will become good political person one day and If they don't it means there not enough criminal mindset.
I don't think it is completely about someone having a criminal mindset, but rather it is a matter of ambition and seeking to lead others and reach a higher status. See, in the world there are people who become criminals and they do not have a political career whatsoever, neither are trying to get one.
Not all criminals are suited to be politicians, though, I could agree with you there are people who reach politics and get corrupted into turning into criminals, it just takes a look to what is going on with the major of New York City. Was he always a crook? probably not, he became one? It seems so.
Ambition turns into criminality.