Again, I can’t comment from any kind of military experience. I’m just...imagining.
We are in a different world than ~~1980. We have an all volunteer military now, and if the upper and middle levels of such a military were to impose a threat of having whatever the lower ranks are in the military for destroyed, revoked, with the threat of imprisonment or trial should they disobey orders, I believe good numbers of soldiers would comply with whatever was ordered. All of them? No. Half of them? Maybe. Very few of those who didn’t follow orders would not, I would posit, actively oppose an internal force ordered to “maintain civilian order” and they wouldn’t have their issued weapons to do so.
If the stage is set with massive tension built up with spontaneous and widespread urban unrest, I don’t think there’s a lot that we can predict about how such a situation might unfurl. I agree that compliance by the military for whatever this admin might come up with could be sketchy, but half the population thinks the country is set up against them and that the country owes them something. There could be a dramatic shift of mood where vast swaths of the population, under conditions of this admin getting booted, might well feel like their window of opportunity is suddenly slamming shut on them and that they might have much to lose.
The all-volunteer military began in 1973. No one in the military by 1980 was there without having re-enlisted (voluntarily, of course), even the conscripts.