Resentment of our progressive taxation system was always at the root of GOP policy as long as I can remember, back into the early 60s.
However, I believe there's a more sinister element at play: when most people become very wealthy, after a period of time the fear of losing it sets in. But the worst effect is that these people start to believe they are
entitled to political power because of their wealth, and thereafter use part of their wealth to gain that control.
And, tied to that belief is the thinking that the teaming masses of everyday folks must be controlled by whatever means necessary - including lying, deceiving, and starving us to death if necessary.
I think recorded history has shown those propositions to be correct many times over......