They aren't predicting the future. They are describing elements of the past and present that other people don't pay attention to or aren't aware of.
Margaret Atwood used what she saw in history and other countries and recognized that we are ALL subject to the cyclical nature of human history. Despite American religious belief in our own exceptionalism.
Butler saw the discontent among Americans who benefitted from a status quo that they saw slipping away from them. She wrote this during Bush Sr's recession and while watching Reagan's cult of personality. But she couldn't predict the financial boom times of the mid-late 90's that delayed this reckoning.