If such a horrifying scenario should come to pass—and pray that it does not—the American People cannot depend solely upon personal arms; they must maintain complete control of the U.S. military forces.
You cut the head off quick. 3-4 days.
Infiltrate DC as tourists and then occupy it.
Control communications.
Some 18 wheelers to block the bridges and roads.
No orders, no action.
/story line
Complete control? Probably not. However, I have never met a liberal, Hillary-voting Gunnery Sergeant, Senior Chief, or Master Sergeant. Never. A substantial majority of junior and mid-grade officers are also patriotic. It's only once stars show up on the shoulders that there is a selection bias toward lacy-panty globalist traitors. The military will not be able to oppose real Americans if our domestic enemies start a civil war, and a large chunk of the military would be sympathetic to following the Oath we all took.