You presume the military will take the side of the President?
Study the history of coups. It’s 50-50 at best.
Being where I am the POTUS is covered by a large majority in the military. They put him where he is. Any malcontents in the Armed Services who side with the enemy are dead men walking.
If you have any young friends in the military, chat with them. Just like the population, the military is essentially spilt 50-50 politically... and both sides openly discuss the what-ifs and what their first moves will be if this day should ever come. They already know who is likely to be on which side. You do NOT want to be near a military base in the first hours of this event actually going hot.