To be inured is to become so accustomed to something negative that you no longer react.
Americans have become so accustomed to being lied to that they don’t react. No matter how flagrant or destructive, we don’t react. This makes us all the more vulnerable to being played. You say you don’t rely on anything politicians say. Yet the future of your children, your business, and what happens when you are old and frail depends on the actions of politicians.