It is a well-known and highly proven fact that unions destroy the free market system and make angels cry. States that do not have unions are more free and prosperous in every way.
So how is it possible that middle-class income actually was higher when union membership was higher, and has gone down as union membership has gone down?
WHAT IS WRONG WITH YOU, MIDDLE-CLASS INCOMES? WHY ARE YOU MAKING THE FREE MARKET LOOK BAD?
It is obvious what is happening here. Middle class income is engaged in a conspiracy with liberal socialist union members to make good, freedom-loving capitalists look bad. This is clearly a case of the middle-class incomes having liberal bias!!!!