A decent article with hard data, albeit a lot of words extrapolated out of one unsurprising fact: with the decline of local newspapers, journalists now mostly live in the cities.
Jonathan Haight has a similar dataset where he shows the remarkably fast and steep political homogenization of academia, with Democrat domination of universities massively increasing over the past ten years.
Lots of people have an intuitive understanding that certain professions like journalism, economics, social science professors are dominated by particular worldviews to the exclusion of all else. But only rarely is this shown with raw data.
