A coup d'état (/ˌkuːdeɪˈtɑː/ (listen); French for 'stroke of state'[1]), or simply a coup, is an illegal and overt attempt by the military or other government elites to unseat the incumbent leader.

It was a coup, just not a successful. I also doubt that it could have been successful, because the old people voting for Trump would get slaughtered if it came to a civil war and the amount of people willing and able to meaningfully fight is way too low.

Perhaps I have too much confidence in the robustness of the American democracy, but I think the military wouldn't even want to run the country and as such they would just organize elections. It's not like the US is some piece of shit country that is easy to run without turning into Haiti. If there is a coup, all the investment dollars leave, the US dollar stops being a reserve currency, and in general the country would go to shit. Nobody with a brain would want their retirement fund to go to zero.

Senile politicians like Trump and Biden should just be put in a nursing home and there should be a maximum age of 53 for being in any position of power. People 30 cognitively decline, so why would you want to take too much risk to run the most important entity there is?