Who was the so-called new middle-class? what was the role of expertise and organization in this new professionalism?

People, who were classified as a new middle-class were people that started to make their own careers (starting business of getting a well-paid job), they have observed a great growth in their salaries at that time and had a lot of leisure time.
Expertise had a very important role - people believed that it is a solution to the weakness of society.