Middle class connects upper class with lower class

The middle class does more than occupy the middle income and middle wealth range in a society's economic distribution. The middle class connects the upper class with the lower class. At best, the middle class performs a linking function in the political structure of the society. 

It might be it was the middle class that the Bible had in mind when speaking about Israel as a stiff-necked people: that the neck, which was hard and which did not convey the upper class' and the lower class' issues to each other, was the self-indulgent middle class.