There is enough protections built into the system, and enough maturity of the system (the "deep state"), that outside of something like war on our shores, no single president can destroy it in one term. But each time its degraded it becomes more susceptible. We just (popularly) elected an election denier. That means future presidents can run this play and get away with it. The most likely scenario now IMO is we get a more cunning strongman who successfully overturns the democratic outcome when not in their favor. We don't have to speculate, as we've see this play out in several other countries. Of course this line of thinking was never a viable political strategy for running against Trump, because its far too abstract for the average voter.
The reality is we are still benefiting from the leadership of some of our more visionary founders and leaders since; but without being reenforced in some way it won't hold up forever. Most people in the US are still under the guise of America being special, and hand waving those scenarios away thinking the worst can't happen here. Which makes it much easier to then vote for Trump, especially if you don't think the climate crisis is real or prescient.
> There is enough protections built into the system
I'm not even convinced of this. The problem is that that many of these protections aren't really legal (at least they aren't all legal), they're conventions and norms. They require the people in power to believe in them, and believe that they're good and useful, or they can be swept aside. The rule of law is a polite fiction that requires people to adhere to it.
Take Elon Musk, for example, who will now likely be involved in government to an alarming degree. By all accounts, he got his start in the US by working here illegally. No problem; rules for thee and not for me. His publicly-admitted drug use should disqualify SpaceX from government contracts. No problem; what are they going to do, cancel them? Musk was unhappy a Delaware judge struck down his Tesla pay package. No problem; reincorporate in Texas and find a different legal framework and judges who like him.
Musk is constantly flaunting norms and getting away with it, and he'll continue to push and ignore these boundaries with whatever government position Trump gives him. Trump does the same, but with a lot more power, and he and his cronies are actually prepared and organized this time, something that wasn't the case in 2016. He has a SCOTUS stacked in his favor, that has already given him broad immunity against illegal acts while in office. He has the Senate, again, and may have the House as well. This time the Senate will temporarily or permanently change the filibuster rules if they're having trouble hitting the 60-vote threshold on things to which it still applies.
The reality is we are still benefiting from the leadership of some of our more visionary founders and leaders since; but without being reenforced in some way it won't hold up forever. Most people in the US are still under the guise of America being special, and hand waving those scenarios away thinking the worst can't happen here. Which makes it much easier to then vote for Trump, especially if you don't think the climate crisis is real or prescient.