I got a little carried away with this response and it's a little off-topic, but I figured it might be worth posting anyway.
I think this has to do with the nonlinear growth in the human-facing complexity of the world over the past 30 years.
Humans aren't getting more intelligent (they may not be getting dumber either, but at the very least, the hardware is the same), but the complexity of the world that we have to engage with has undergone accelerating growth for most of my lifetime. The fraction of this complexity that is exposed to 'normal' people has also grown significantly over that period of time with the 24-hour news cycle, social media, mobile internet, etc.
It's obvious that at some point in this trend any given person will start running into issues with the world that are above their complexity ceiling. If this event is rare, we shrug it off and move on with our day. If this becomes commonplace, we start to drown in that complexity and desperately cling to sources of perceived clarity, because it's fucking terrifying to be surrounded by a world that you don't understand.
The thing that the right has done really well and that the left has generally failed to do in my lifetime is to identify sources of complexity and provide appealing clarity around them. This clarity is necessarily an approximation of the truth, but we NEED simple answers that make the world less scary. People also, as a general rule, don't like to be lectured or told that they are part of the problem -- the right never foists any blame upon the people it's targeting.
In my lifetime, the left has pretty consistently fought amongst ourselves over which inaccuracies are allowable or just when we attempt to create simplifying approximations. Instead of providing a unified, simplifying vision for any given topic, the messaging gives several conflicting accounts that make it easy to see the cracks in each argument, and often serve to make the problem worse. If you're competing with another source of information that is simple, clear, and makes people feel good (or at least like they are good), you will always lose if you do not also achieve those three things.
In the vacuum created by a lack of simple, blameless, intuitive messaging from an (arguably) well-meaning left-leaning establishment, the intuitive (though generally wrong and often cruel) explanations offered by the right have found huge support and adoption by people who need someone to help them understand the world. Because both messages are approximations of the truth (and thus sources of verifiable inaccuracies) people just choose the one that makes them feel better.
tldr I think we've hit a point where:
- The world is too complex for many people to independently navigate
- People need rely on simplifying approximations of the world
- Media provides these approximations, often in bad faith
- Sources of credibility or expertise often provide these approximation in good faith, but can't agree on which approximations are the 'right' ones
- Good faith messaging often either fails to simplify or makes people feel bad/guilty
- People are sick of feeling bad or guilty
- People associate expertise with being scolded over things that don't feel fair or fully accurate to them
Thus people often reject expertise out of principle, and just believe whatever Fox News tells them because it feels better.
ALSO: People who believe the 'right' things are often pretty shitty to people who don't (it goes both ways, but the other direction doesn't matter for this post). I've been guilty of this. This just further galvanizes the association between expertise or the 'right' ideas/people and feelings of resentment/guilt/shame for these folks. They may not understand what you said, but the do understand that you were talking down to them, and they hate you for that.