Authoritarianism and anarchy are not opposite ends of a spectrum. Furthermore, there are many that reasonably believe that certain forms of structured anarchy are a good thing, and not just teenage punks, but also intellectuals and academics.

Regarding the US falling to authoritarianism, there are at least two factors: 1. Most people are in a state of conditioned helplessness where they don't feel there is anything they can do to affect change. 2. Most people don't have minds of their own but just parrot what they hear in the media that aligns with their party. These two in conjunction leave an opening for someone to execute a soft coup. In fact a draft Trump executive order to discard the election results was released recently. He had convinced his base that the election was fraudulent. Seeing how far Trump got at eroding democracy, imagine someone like Trump but competent in the same situation. Every democracy that has gone authoritarian had plenty of branches and politicians and checks and balances in place.