Reading the parallel histories of the Roman and American empires, it's fun and useful to try to locate where we are today by finding the same approximate place in the sequence of the slow Roman slide into oblivion. It looks to me like we're at the "crisis of the third century stage of unravelling, as we attempt to deal with our own 21st-century disaster.
Just as Bush II took office 21 years after Reagan first sat on the throne, so the first Gordianus followed Reagan's opposite number, Septimius Severus by 27 years, and presided over the near-dissolution of the whole shebang due to civil war, financial crisis, and plague. He ruled for a little over a month in 238, and committed suicide on hearing of his son's death in combat.
Then came Pupienus, not only my favorite name of any emperor, but was the first in a line of tough old soldiers who were chosen for the job by the army, then quickly discarded. The military establishment, who were well aware that they alone chose the emperor by this time, but were very fickle, killed Pupienus and his co-emperor Balbinus, with whom he did not get along, afer they'd been in office a bare couple of months.
Philip I, called the Arab (he was from Syria) ruled for nearly five years and presided over the thousand-year jubilee of Rome's foundation, a very nervous and not particularly joyous occasion. He was killed in battle against a rival general supported by his own troops, Decius.
Hostilianus, the son of Decius, took over after his father was killed fighting the Goths. He ruled briefly in 251 and died of the plague.
Look, it's Claudius Gothicus again, my all-time favorite spiky-hat guy, whose brief reign was going well (he was successful both as a general and a ruler) until the plague took him in 270.
Some of these guys were capable and honest, others were incompetents and scoundrels, but all were equally helpless in dealing with the simultaneous, cascading disasters of the time in government, war, public health, and public finances.
The crisis of the second century finally ended in 285 with the accession of the Emperor Diocletian, who re-organized the government, reformed the finances, and did what he could to shore up security along the frontiers. The Roman Empire weathered the crisis, and went on to last another 200 years.
Likewise, the American empire is not done yet, although ecological meltdown, the modern day version of plague, make our future cloudy and uncertain.