[ I half expect him to suspend the constitution, dissolve congress, and the supreme court, then declare himself pResident for life instead. ]
Who the hell would stop him in Washington, besides Cruz and a few stalwarts in the House?
No ONE!
For the sake of argument, if the President were to dissolve the other branches of government in a coup d'état, he would need the military to back him up and violate their oaths to the Constitution in the process. Were this unlikely event to happen, Cruz and the other stalwarts would be interned "for their own safety" on a military base somewhere, along with perhaps most of Congress and the Supreme Court. Such a move would be accompanied by government agents going door to door, confiscating all arms "so that the violence from the Ferguson grand jury decision cannot lead to yet more violence."
So the question would be: Would the military back such a plan -- or would the military remove him themselves with their own coup d'etat? I don't know the answer. A worst case scenario would end up with factions of the military fighting each other in a nuclear civil war.