Well, if the president is a Republican, everyone would just follow orders, of course.
Now are you happy?
What exactly are you trying to get at? A coup attempt, even by the president, would be resisted and stopped.
The reason your question won’t work is that there’s no way the President, Congress, the Supreme Court and 3/4 of the state legislatures would just wake up one day and decide make America a dictatorship. Of course political changes could happen such that America becomes a dictatorship, but your scenario essentially presumes workable mind control of a couple of hundred people.
So if your plotters could only mind control those couple hundred people, eventually–within a couple of months–they’ll be pulled from the state houses and governor’s mansions and capitol buildings and strung up from lampposts. And then constitutional government would be restored.
Any realistic scenario for an American dictatorship has to include a large public consituency for dicatatorship, not a tiny clique of top officials. The Nazis didn’t take over Germany by secretly getting Hitler into the Chancellor’s office and then he proclaimed dictatorship and everyone had no choice. Yeah, the majority of people in Germany didn’t want dictatorship, and the vast majority didn’t want another war. But the Nazi party got a plurality of votes, even though the Nazi platform was openly contemptous of democracy. Caesar didn’t become dicator for life merely by declaring himself dictator, be became dictator because he was enormously popular, the Republic was tearing itself apart in repeated civil war, Republican government was failing. And Caesar’s legions weren’t loyal to Rome, they were loyal to Caesar himself. But such legions do not exist in America today, or in any first world country.
So any scenario of an American dicatorship would have to include an economic meltdown and a disasterous war (and I’m not talking about a mere pinprick like being chased out of Iraq or Vietnam), creating a large and dynamic public movement of impoverished that despises democracy, leaders of that movement getting into positions of power, any potential opposition movements are disorganized and have discredited themselves and are despised, the true believers are willing to spontaneously use gang violence against anyone who publicly opposes the new regime, the military backs the new regime, the situation being so screwed up that the majority of the public who don’t subscribe to the new ideology take a wait and see approach, figuring that they can’t do much worse than the current crop of losers who got us into this mess, and the new movement has some sort of plan for the country that can at least work for a short time…expel the Jews or the Mexicans, government make-work jobs, cancelation and repudiation of debts, nationalization of industry, whatever.
If a determined and united plurality of Americans work to impose dictatorship, dictatorship we will have. It doesn’t even take a majority. But that plurality is not a few hundred people. Yeah, in third world countries you can stage a coup with just a few key military officers and government officials. But not in America or any other democratic country. These third world coups don’t replace representative government with dictatorship, they replace one gang of oligarchs and kleptocrats with another gang. The public isn’t outraged because they had no loyality to the original gang in the first place, and there’s always a chance the new gang will be better than the old one at least for a while.