[old-ager]

> I’m not sure how the scum of humanity keeps rising to the political top in western countries

Because they want power and will do and say anything to get it. You knew some of them in HS.

[Garth Tater]

"Because they want power and will do and say anything to get it."

Don't forget the other half of the equation. There are rich and powerful people that want our leadership positions to be filled with that type of person. They have built a system that encourages  cream  scum to rise to the top and rise to the top it does.