Readers

The text is the introduction to the book Hillbilly Elegy. A Memoir of a Family and Culture in Crisis by J.D. Vance, meaning that the intended readers of the introduction are obviously the intended readers of the book as a whole. 

Vance himself provides many hints about what kind of readers he hopes to reach in the introduction. We see the first clear example of this on the first page, when he talks about his reasons for writing this book:

That is the real story of my life, and that is why I wrote this book. I want people to know what it feels like to nearly give up on yourself and why you might do it. I want people to understand what happens in the lives of the poor and the psychological impact that spiritual and material poverty has on their children. I want people to understand the American Dream as my family and I encountered it. (ll. 25-29)

The phrasing makes it clear that Vance's intended audience are people who do not have direct experience of these issues, but are instead hoping to understand them as outsiders. In practice, this probably means that his main target audience is middle- a...