A question I wish Rand Paul would raise now
His flibuster got the White House, rather reluctantly it would seem, to state that a President does not have "authority to use a weaponized drone to kill an American not engaged in combat on an American soil."
Nice to know. Further question: do situations like Waco or Ruby Ridge constitute citizens having "engaged in combat"?
At Waco, the government deployed an M-1 Abrams and armored personnel carriers, military aircraft, and even a battlefield robot (which kept breaking down).
UPDATE: the "incident commander" had an Abrams. The building was broken up and gassed by Combat Engineering Vehicles, while APCs contributed CS gas projectiles.