On the Right : "Might is Right" - Fascism, Nazism
On the Left : Nihilism-> Anarchism
Fundamentally it is an anti-religious influence on both the Right and the Left
Because philosophy concerns a search for the truth. Cogitation on right and wrong
But in the relativist view the will to power is what matters
Or it can mean a form of extreme individualism coupled with a tendency to view society in terms of power equations. Basically Marx meets Nietzsche (that's what the new Left is about)