Caleb has been regularly listening to a popular weekly podcast on political issues and current events produced and hosted by the well-known journalist Ezra Klein. Over time, Caleb has noticed that his political opinions have become increasingly similar to Klein's. A sociologist would describe Ezra Klein as a(n)

Iam not sure sorry

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.