In this case I think all that's going on is that the writer has already used the phrase "working classes" earlier in the sentence, and is following a convention that recommends avoiding repetition in this sort of case.
It's more than just that. If you read the initial part of the sentence (that dhsysusbsjsi cut off) you can see that the author is paraphrasing a worry of the ruling class. In this context it's natural to use the kind of vocabulary that they might have used in their own thoughts.
Critically it’s redundant in the paragraph, much like ‘dark and stormy night’. The point is to convey something else which is made clear by the redundancy.
