They can, but you have over a million members of the military who have all sworn an oath that they will "obey the orders of the President of the United States." If they had all sworn an oath that they will "obey the orders of General McEvilFace," it would be a lot easier to maneuver all your coup pawns into place even over the protestations of the president, even without those soldiers needing to fully realize that a coup was being set up.
Americans disagree about a lot, including how to interpret the Constitution and which parts of it are more or less important. But I would really hope that myself and any other random American can at least agree that our Constitution is the rule book that we must all live by and that it is ultimately what binds us as a nation.
It's interesting that this shared allegiance to the Constitution was still strained to the breaking point 160+ years ago. I wonder how U.S. military leaders must have felt when huge swaths of the military (and military leaders) decided that bond was no longer strong enough for them to maintain their loyalty to it.
I agree that's what Americans should agree on, but did you miss the part where certain very prominent Americans have been vocal about how inconvenient the Constitution is and that any provision of it which they disagree with should be 'terminated'? I'm afraid we're not all on the same page wrt the Constitution.
> did you miss the part where certain very prominent Americans have been vocal about how inconvenient the Constitution is and that any provision of it which they disagree with should be 'terminated'
Those prominent Americans include the original authors of said constitution: they always knew it would be a living document to be modified via amendments. Constitutional "originalists" who believe we should be totally beholden to a 240-year-old document with no changes are the ones who are not following either the spirit or the letter of the constitution.
I'm not talking about originalists, and I'm not talking about amending the Constitution through legitimate political process. I'm talking about people who feel that parts of the Constitution that they do not like they simply don't have to follow. That's about as unAmerican as it gets.
They can, of course, but it's harder for coup-ing superior officers to make dozen of thousands of 20y.o. Grunty McGruntFace follow them to overthrow the government when the very oath they swore was to that government, and that this oath explicitly states they don't have to follow General von Teufel orders in this case.