Last Days of the Roman Republic
We all recall - OK, maybe I don't quite really - how the last decades of the Roman Republic saw repeated convulsions as various families of the oligarchy competed for dominance, culminating in famous plays by Shakespeare and Shaw. Crassus got whacked by the Parthians, Pompey by Caesar, and Caesar - but that's another Shakespeare play. And that was the end of the Republic, after Octavian, Caesar's adopted son, whacked his erstwhile ally Antony, and made himself emperor.
Somehow, now that the 2016 election is starting to look like another Clinton-Bush rematch, the atmosphere feels grimly familiar.