yeah, I think he's playing a little fast and loose with the word underclass here. Perhaps it's simply for dramatic effect. However the main point to me doesn't

yeah, I think he's playing a little fast and loose with the word underclass here. Perhaps it's simply for dramatic effect. However the main point to me doesn't hang on exact parsing of this word - one could imagine related terms (working class, the have-nots, the little people, the proleteriat) with similar effect. It does matter exactly who he's talking about, but parsing this differently is not exactly at the level of Refutation of the main point. the whole theme is rather high level and abstract to begin with, anyway, which is not quite at the level of precision of concrete examples.