Lots of similar sentiments were expressed in Weimar. And Hungary about a decade and a half ago. I'm not saying you're wrong, but it's more complicated than that.
Let's assume for a minute that it is certain they will trash the constitution and try to create an autocracy or purely electoral democracy (like Putin's Russia, where elections are in fact held, but they aren't free or fair). In that case, I would argue that we would have an obligation to trash the constitution ourselves, because then we will be the ones who can build it back into something like an 21st century update of what it was -- whereas they are going to build into white Christian nationalism. Yes, I'm aware that "we're the good guys" has been the mantle of any number of totalitarian movements (e.g. Maoism) and that's what makes all of this dangerous. But faced with a choice between a certain right-wing dictator and a possible left-wing one, I would go with the latter.
But you're right -- it's not inevitable. So what difference does that make? Hard to say. The consequences are still so potentially terrible that it's an unacceptable risk. On the other hand, the choice between a possible right-wing dictator and a possible left-wing dictator becomes less clear. To me, it's climate change that tips the scales here. The real danger of Trump isn't necessarily what he will do to America -- after all, at least some Americans will get what they chose -- but the consequences to the planet. Rolling back climate progress when in reality we need to be doubling our efforts will prove catastrophic and probably irreversible, absent the emergence of some fantastic technology.
Obviously my opinion carries no weight so it's idle chatter.
