There are no guarantees but the fact that we are a republic has already saved the United States government from sliding into authoritarianism at least once. If not for the guardrails set up at the founding, the United States and most of the world would be controlled by dictators.The fact that we are a republic does not seem to eliminate this tendency
By far the greatest populist ever to take control of the United States was FDR, and if the Supreme Court had not struck down FDR's NIRA for overstepping the guardrails then we would have gone the same way as Italy, Germany, Russia, etc. And if we would have gone, then the world would have gone.
As for the elites crying about being questioned or doubted, eff them. No one should be blindly trusted. Show me an elite who whines about being doubted and I'll show you an elite who is pretending to be more certain that they truly are.