Nor is it just news media bias. As we saw with the recent revelations in the New York Times story, it extends to (anti-)social media as well (see The New York Times: 14 November 2018: Sheera Frenkel, Nicholas Confessore, Cecilia Kang, Mathew Rosenberg, and Jack Nicas: “Delay, Deny and Deflect: How Facebook’s Leaders Fought Through Crisis”). It also happens in non-news programming.
There is a tendency to believe that if the media is biased against conservatives, it can’t also be biased against progressives. This is clearly false, as bias is anchored on difference, and the media has its own political culture to defend.
The media is biased against conservatives in some ways, and some of those biases are reasonable; for example, being pro-environment and therefore biased against those who are indifferent, at best, to the environment. But the media is also biased against progressives, seeming to believe that math works differently when it applies to money, and therefore that a universal healthcare system is rainbows on roses and whiskey-toting kittens.
The right-wing uses this effect as a handy political signal. They made hay of the IRS looking for political groups in social welfare clothing. They made hay of (anti-)social media having a bias. But we know in both cases that the IRS also targeted progressive groups and that Facebook has a bias against progressive criticism.
The constancy of the “Democrats in Disarray” narrative is such that you could set your watch, if you still wore one. The media dutifully revives the notion of the “fiscal conservative” like it’s a civilian costume on a superhero. Poof! Where did the tax-slashing big-spending party go? Nobody here but us arch-penny-pinching conservatives.
We saw the ultimate absurdity of this media tendency on several occasions in Trump’s first year or so. He would read a speech, and the media actually thought it was worth pretending he was presidential. They still give enough gravitas to him, merely for occupying the oval office, that they’ll print his lies as headlines.
Media bias is a thing. It comes in many forms. Not all of them are unreasonable, but every one of them is acknowledgable, and those that aren’t reasonable should be discarded.