(I'm not American)
The constitution also defines the process of changing the constitution itself (article V), and it does not include a way for Mr Trump or his party to do that as they do not have the required two thirds majority in both houses or in state legislatures.
Importantly, there isn't even a way for him to whip up emotions in a referendum in order to change the constitution.
The judiciary is not controlled by any party at all. Supreme court judges are appointed for life to prevent arbitrary interventions by other branches of government.
And in practical terms, did you really get the impression that Trump has unwavering support even just among the legislators of his own party? Did you get the impression that the FBI acts on Trump's say so? How about the courts?
No, what I'm seeing is a wannabe autocrat who is kept in check by an extremely robust set of institutions, constitutional arrangements and by a lot of principled individuals inside those institutions.
I don't see Xi, Erdogan or Putin getting investigated by their own police or courts, having to fear impeachment or face the sort of (well deserved) journalistic onslaught that Trump has had to face.
You realize that if they get this bad, it's too late to take action, right?
Here's the same logic, applied to a different field: "Oh, yes, you keep talking about climate change but I only see mild temperature increases and I'm not even sure they're man-made. I don't see the sea level rise and catastrophic outcomes you're talking about. If we start seeing those, we'll take action."
It'll be too late.
That's exactly why so many autocrats and parties with an authoritarian bent try to change the constitutions of their countries in order to give themselves greater powers.
Trump hasn't done that because he can't. And I think this deserves far more attention than it is getting. It is something other countries can learn from.
Does it. A first-past-the-post system which reduces everything to two parties. Low voter turnouts. High gerrymandering. Terrible voter accessibility laws. Three branches of government end-to-end owned by only one party. And a ton of money in politics thanks to Citizens United.
I'm sorry, but "robust democratic institutions" and "checks and balances" at this point are things americans tell themselves to sleep better at night. If you step back, you start seeing just how far gone the country is.