I obviously can't do your writing for you, but I can help you think about who in our society might feel this way. It's a great quote , and I'm confident there are plenty of people who might feel as if the entire world was not only indifferent but actively against them.
In our current economic situation, there are people who are losing their homes despite being hard-working, faithful, taxpaying citizens. The banks have been relatively hard-hearted and impersonal, making people feel as if all their hard work and investment has been in vain.
Obviously the homeless citizens of our country could feel this way. And certainly those who are living helplessly in poverty would have the right to feel as if they've been somehow overlooked--or worse.
What I think of most, though, is those who survived Katrina. They were herded and moved and shifted, and they lived in horrifying conditions which went largely unnoticed or unimproved. Many would say the same thing today, years later.
This quote from The Bean Trees feels very personal, and I have no doubt that there are people in America who recognize this sentiment--and have actually spoken these or similar words. If you write from this perspective, you'll be effective.