It's no coincidence that Fox News' and Bill O'Reilly's audience skews older, from what I remember.
IIRC, all cable news skews older. Even MSNBC's highest ratings during Maddow, etc. are in the 65+ grouping.
But I wouldn't expect "millennials" (aka everyone under age 45) to sit and watch news programs anyway. Especially with the internet. John Oliver's show putting his extended segments on YouTube (not even only his shows website like the Daily Show) entirely gives it more traction than people watching the show probably ever would.
Regarding the discussion of the media's position writ large. There's this weird notion of journalism that has never been true or was only true for a short period and it's best illustrated in the arguments over
games journalism. This notion that there's an objective single pipeline of information. When there's an inherent bias simply in what you choose to cover or not cover.
Most of journalism's history has been as a failed business, propped up like art by patrons. This arguably frees it from chasing "ratings" even if it may stick it closer to its patrons interests. And it's almost always been openly biased. You can look at the names of newspapers in the United States and realize this as all sorts of them have Democrat or Republican in their names because they started as partisan journals that later became "objective" in their focus.
Most newspapers and media outlets didn't have full time D.C. bureau staffs until the 1980s. The seeming groupthink can stem simply from the social circles and access more than anything actively partisan.
This Town depicts it not as something sinister that there's all these powers in the swamp secretly plotting but more of a factor that you know this guy who knows this guy when you need to talk to somebody about X for your story.
The Washington Post has long been considered the friendly paper to the Pentagon and CIA. It's probably no wonder that they were on the front lines of publishing faulty stories about the Russian hacking of power plants and PropOrNot without second guessing or bothering to check their sources.
The New York Times and other longtime media's open fretting about how they aren't oppositionial enough to Trump and then turning back after the election only to again reverse themselves in some kind of industry crisis says more about what they weren't doing that only the "shock" of Trump apparently has made them reassess. Especially as PD points out, all the endless fretting over Trump's refusal to follow some unspoken protocol being the crisis of everyday. Moving the daily press briefing (of which no news ever comes out of because it's a show done after the off the record briefing earlier) and including internet outlets is supposed to be something yoooge and just how unbelievable and how could he. The entire thing was originally created for easing the propaganda purposes of the White House ffs, that's all it ever does!