The fact that Mr. Trump is not able to run the USA the same way as his companies is speaking to the strength of the American democracy. CNN is not shut down and high ranking Democrats are not in jail. In fact, more of his people are in jail.
If Mr. Trump wins in 2020, we will have another four years like the last four. USA will not devolve into a dictatorship. Mr. Trump will be 80 years old by the end of his second term; he will not stamina or political support to go past the two terms. There will be no obvious successor to his Trump party.
But the next populist leader might be a danger. That person will be younger, smarter, and understand something about psychology and sociology to manipulate the masses more effectively. And he/she will learn from the Trump presidency.
But this outcome can be avoided if 1% of Americans decide to start building a non-partisan system of governance.