There is nothing unique about Eugene. Every city I've lived in had a lot of friction between the haves and the have-nots. Oakland, California comes to mind, lived there for four years, tense. I spent several years in Portland and they have the same problems we have here. 

Poverty breeds anger, which gets expressed and generates anger in return. It's not just the homeless, who are the tip of the iceberg. Working-class people in general are having a hard time surviving the US economy, and we aren't happy about it. Inequality is growing. We had better do something about it. No economic justice, no peace.