Not another nitwitted application of Gibbon's interpretation of late antiquity to the current American situation. Surely if one wants classical analogies, the late Roman Republic, or the Athenian over-extension in the conquest of Sicily are more apt.
Gibbon is really quite useless as a source of apt historical analogies, as it was he who invented the notion that the non-event of the retirement of the last Western Augustus to a villa near Naples in 476 constituted the "Fall of Rome". The Empire went on for nearly another millennium, with its capital at Constantinople, albeit dwindling to a city-state in its later years. At the time no one noticed that anything much had happened. Indeed when Charlemagne had himself crowned Emperor, he didn't think he was starting a new Empire, only reviving the dormant office of Western Augustus. it was only when the Empress Irene declined to recognize his claim that he proclaimed his Empire to be the "Holy" Roman Empire and began slandering the organic continuation of the original Roman Empire as the "Empire of the Hellenes" (in those days "Hellene" had the sense not merely of Greek, but of pagan Greek, so it was slander.