But the oath??? I am not an historian, but I am pretty sure the "and domestic" part of the oath did not have in mind taking down the President, but instead is focused on things like Shays' Rebellion and, yes, the Civil War. I don't think that the inclusion of "and domestic" was aimed at replacing the President of the United States. Yes, we sail in uncharted waters these days, but getting the military involved is a bad, bad idea. Why?
- The factor most associated with coups d'etat is previous coups. That is, once norms against such stuff are weakened and once it is seen as thinkable and even acceptable to have the military seize power, they might come back again and again.
- When militaries get into power, they get corrupted by it. They will come in, saying it is just to protect democracy from the corrupt and the inept, but then making political decisions such as who gets what will taint the military. They might just see "the national interest" requiring more military spending, less oversight, whatever.
- You think things are divided now? Just wait until some officer orders his or her troops to do something in the political sphere, such as shoot at protestors or confront other military units that see things differently? No good can come from that.
What recourse is there when Trump abuses power? The obvious ones: vote and protest and pressure Representatives and Senators to do their damn job. Boycott media outlets and their corporate sponsors if they are supporting Trump and his abuse of power. Asking the military to do something here is kind of like asking someone else to do one's own job. Getting Congress to act, challenging the President--that is the job of citizens and the media, not the armed forces.