How are American attitudes towards poor people illustrative of what Smarsh calls “upper-class supremacy” (Smarsh 4)?

In “It is Expensive to be Poor,” Barbara Ehrenreich deconstructs the alleged “culture of poverty,” rejecting the idea, advanced by lawmakers and accepted by Americans generally, that poor people are not hardworking or ambitious. Sarah Smarsh, in her article, “Poor Teeth,” calls out the injustice and hypocrisy of Americans ridiculing those who cannot afford dental care. How are American attitudes towards poor people illustrative of what Smarsh calls “upper-class supremacy” (Smarsh 4)?