Either way, it's beside the point: if there is one lesson to remember from the 20th Century it is 'never support an authoritarian'.
Some parts of the country never really recovered from 2008. Obama took the smug liberal approach of telling people it was all over when it clearly was not all over. The country was primed for the Tea Party to step in and offer the promise of a remedy. You and I both know that the remedy was bunk, and it was just a rebranding of the same old far right, who saw that the Evangelical Christian movement that they were previously allied with had lost influence. And so into the propaganda brainwashing funnel went millions and millions of people.
Right wing media was already powerful and influential long before Trump started his own social media company and Zuckerberg switched sides. Blaming social media doesn't make sense either, because if it wasn't for social media, it would've been something else.
Social media became a major force after 2010, and indiscriminately affects nations around the world.
Since the nations with rising authoritarian movements have little else in common, social media clearly is the cause.
The public, before social media, was better informed about the world. They have access to much more information now, but that means little when the information they consume first has been sharted out the asshole of some idiot podcaster.
For various reasons, social media incentivizes knee-jerk antiestablishment takes: "Get angry! The MSM is hiding the horrible truth we are about to share with you! Like and subscribe or be kept under their control!" That is why any nation with social media, and a sufficient number of gullible citizens, tends towards violent revolution and pugilistic leadership.