There's a bit about that in the "Tyranny of the Intolerant" section. Imo the article isn't so much making a case for that as it is lifting quotations wholesale from Timur Kuran as a sort of appeal to authority to justify it's own narrative. It makes out like it's obvious that Kuran's work explains the rise of Trump and Fuentes, whilst Musk's hijacking of Twitter strikes me as a simpler more natural explanation.