Pretty much if the military felt the way we do then they go and arrest Congress and there would be no need to take up arms.
On the other hand if antimilitary liberals has had control of the government and military for any length of time this is what happens. They promote those who share their viewpoints and they don’t promote those who don’t. They cut the pay and benefits and perhaps enact a draft. An army of draftees is easy to control as the Soviet Union shows. The patriotic real good soldiers, many from long time military families will either not enlist or will get out and those who remain can be easier controlled and lead than if they got out.
Look at the New Orleans and some other police forces, at one time they had good cops who respected and enforced the law. After long time Democratic liberal rule the cops are pretty much the same as the criminals and didn’t hesitate to take the guns away from legal owners.
Within ten years of liberal rule the greatest military in the history of the planet could be turned into a national version of the New Orleans cops.
First off, they still have a CIC that they respect and secondly you do not do something like that until it absolutely becomes necessary as it is an act of treason. I am sure there are a good noumber that would love to do it now, however, now is not the time to do it. On top of that it would mark a change in American history that may or may not be desirable.