[throwaway894345]

I would go farther and make it relative to clusters of people on, say, Twitter. If an outlet is concerned with a lot of things that the progressive cluster of Twitter users is talking about (more so than many other outlets), that’s a strong indicator that the media outlet (and other outlets in its media cluster) is also progressive.

[hwers]

I'll just throw out a comment (even though this is mostly a thought experiment) that doing any type of twitter analysis is either nearly impossible (in the scraping case) or prohibitively expensive (e.g. using their API). They've really shut off access to third parties in the last few years. (Just thought I'd mention it since the parent post continues this pre-2015-ish idea that still floats around that using twitter for projects could be a thing.)

[throwaway894345]

Fair enough, yes, Twitter was intended to be an example of a mine-able medium where people express political opinions, but to your point mining Twitter data may be more difficult than I imagined.