[Dudhbbh3343]

> have white sub-groups like Irish or Italian

Right, but are those sub-groups still all that relevant in the context of race in America?

It's been a long time since Irish-Americans have been treated differently than British-Americans, for example.

I would say grouping all white sub-groups together makes as much sense as grouping all black or Asian sub-groups together because generally racial dynamics today are viewed as occurring between White, Black, Asian, Hispanic, and Native American groups. Further granularity is rarely considered in informal language.