Quite simply, because they've made deals.
Just like in Iran, wealth and power go hand in hand here. The current Trump administration values those with wealth and cares little about those without wealth. Currently, controversially, pushing tax cuts for the very wealthy and tax increases for those with middle to lower income. It is a trend that should be reversed, but we are seeing no evidence of that.
Why do we tolerate such unfairness in the US? Ignorance. Pure voter ignorance.
I would not want to accuse Iran of the same thing - but I would be inclined to think a similar thing is true.