You’d think a hegemony with a 100-years tradition of upkeeping democracy against major non-democratic players, would have some mechanism that would prevent itself from throwing down it’s key ideology.
Is it really that the president is all that decides about the future of democracy itself? Is 53 out of 100 senate seats really enough to make country fall into authoritarian regime? Is the army really not constitutionally obliged to step in and save the day?
I’d never think that, of all places, American democracy would be the most volatile.
Your first question is pretty philosophical. All I can say, is that most representative governments place a huge emphasis on giving the people the power to write their own collective destiny.
A military takeover based on the desires of a minority of citizens would violate that principal. I don’t think any reasonable person can call it saving democracy.