I think there has always been a permanent underclass but it was shrinking. You are right, it might now be growing.

In the past it was mostly a division based on race and gender. Now it is less so and more based on class, which does still have some racial and gender factors.

My fear is that I will have to look these underpaid workers in the eye and count on their services. Will they blame me for their precarity?

In the past these poorly paid people were keep mostly out of sight in factories or working nights and weekends. Now they are providing home health care, waiting tables, tending bar, working retail or cleaning houses.

They used to be poor immigrants or poor women who kind of expected to be paid poorly. Now it could be anyone and they probably have a chip on their shoulder.