I find it surprising if Brazil meets this criteria:
> capital is the only thing separating one set of humans from the other, and that separation is large, and the overwhelming majority of humans are in the underclass.
Obviously, it's a matter of degree. You could reasonably argue that any capitalist society meets the criteria depending on your definition of "large", and depending on how you interpret the "capital is the only [sic] thing" part
You could also argue in the other direction: capital is never going to be the only thing separating one set of individuals from another, because we sure like to keep finding ways to label ourselves different: ethinicity, religion, political ideology, sex preferences, eye color...
Then again, maybe this is why Brazil finds itself in this steady state of economic inequality and endemic violence but without critical mass for a civil war: the same diversity that makes Brazilians apt at navigating conflicts is what makes us incapable at finding a common enemy and building an united front?
> capital is the only thing separating one set of humans from the other, and that separation is large, and the overwhelming majority of humans are in the underclass.
Obviously, it's a matter of degree. You could reasonably argue that any capitalist society meets the criteria depending on your definition of "large", and depending on how you interpret the "capital is the only [sic] thing" part