What's causing the "populism" (which I assume means "democratic movements that the left don't like") is actually quite simple: the left are wrong and bad.
Otherwise, the claim is arrogantly that all these people voting in characters like Trump are simply stupid and driven purely animalistically by emotions like hate.
Which indicates, by the why, where most leftism flows from: narcissism.
But as to why the most recent burst of it happened, I'd offer two factors.
The first is that the western left had had a very successful run and achieved complete cultural hegemony (which they still maintain to this day - just weaker).
One landmark in this was they successfully caused a free flow of migrants from "Syria", with Merkel saying an unlimited number will be accepted.
Another was Bruce Jenner put on a dress on the cover of Rolling Stones and everyone was made to call it "heroic".
Several others could be mentioned, like having achieved a forced redefinition of marriage (using a different word with same legal standing was simply not enough, they had to achieve thought control), first undemocratically (prop 8 etc) and then successfully democratically in a formerly culturally conservative stronghold - Ireland.
Note that none of this was working class leftism. It was a new, more virulent strain, elite driven, through various desires to subvert and consume. If you were to ask the question "who actually benefitted", the total number of people would be very small.
Whereas in previous cycles, when the left was weaker, people could frequently mock political correctness etc, this time the hegemony was total. If you spoke up anywhere about any of the left's agenda, you were a baddie.
This caused a widespread seething of the population, many people who could see, and get angry at the fact their societies were getting destroyed by a malevolent ruling elites, and could do little about it except grumble.
Which led to the internet outlet. That was the one place remaining where dissent could be spoken.
So yes, it was the internet that undermined your agenda, because it was too difficult to control.
Hence why that's where the left have shifted their focus as of late. Jailing people for tweets, chat surveillance, discussing VPN bans, etc.
But the motivation underneath is extremely simple: you're actually that bad that people are willing to vote in characters like Trump for the faintest hope he can at least slow you down.
So the solution to populism is simple: care about the populace, rather than just yourselves, and stop going out of your way to hurt them.
1962 https://en.wikipedia.org/wiki/The_Image:_A_Guide_to_Pseudo-e... predicts that television performers will eventually overtake and outclass conventional politicians
1964 https://en.wikipedia.org/wiki/Understanding_Media Marshall McLuhan predicts that 'television' will displace the 'Gutenberg Galaxy' of print but it could do it in the form of ABC/NBC/CBS but take the same (physically, later functionally) screen attached to an image synthesizer and versatile communication network and you get YouTube, which does.
1971 The Information Machines: Their Impact on Men and the Media by Ben Bagdikian reports on studies at the RAND corporation predicting that something like the WWW would come online in the early 1980s -- and technically it did in the form of services like Compuserve and The Source. Bagdikian pitched this vision to leaders in the media industry and was roundly rejected and was the origin story that led to his famous https://en.wikipedia.org/wiki/Ben_Bagdikian#The_Media_Monopo...
In the 1970-1995 period the development of communication networks lagged behind all predictions because incumbents didn't want to make investments -- had they done so, Google, Facebook, Amazon and such would have been strangled in their cribs. The WWW seemed to take over so fast because it was actually delayed ten years and the technology to realize it had been sitting around latent and underutilized.
1975 https://en.wikipedia.org/wiki/Legitimation_Crisis_(book) by Jürgen Habermas outlines a conflict between "expertise required to make decisions concerning complex science and technology" and "public participation" that he sees no way to resolve.
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The "legitimation crisis" is the immediate crisis that Fukuyama sees, but connected to it is a long term breakdown in community pointed out by the likes of Nisbet and Putnam which manifests as a breakdown in household formation. We're pressing the panic button right now to save children who are halfway through school but... boy we are in trouble.
nephihaha•1h ago