We don't need the military to do anything to subjugate the population when there are 120k+ Federal law enforcement officers that answer only to the politically appointed DOJ. People tend to forget events like Waco. It won't be militias or the military or the police that will initiate "change", it will be the feds themselves.
So no, a military coup isn't what it will take. The feds will send the military off on some manufactured war, then seize control.