It makes sense to divide Hispanic and non-Hispanic White if we are performing this categorization for the purpose of analysing discrimination. This is because traditionally Hispanics have been discriminated against by non-Hispanic Whites. The same could be said for the Irish, or Catholics... but Protestant/Catholic discrimination seems to have simmered down in the US.

Or to put it simply: Does a Hispanic in California currently experience White privilege? If no, then they should be counted separately.