The Republic was dead in fact if not in word since the middle of the 2nd century BCE. As Plutarch (life of Aemilius Paulus) said, the illegality had become so general that the Senate was forced to close the mines of Macedon after the Third Macedonian War, not to punish Macedon but to protect her from the rapacity of Roman officials. The fates of Publius Rutilius Rufus (in 92 BCE) and Lucius Licinius Lucullus (in 67 BCE) show how great the control of the oligarchy was and how dagerous it was for a magistrate to be both honest and competent. Cnaeus Pompeius Magnus (who had been instrumental in depriving Lucullus of his command), Brutus (whose fortune had been acquired by charging four times the legal rate of interest), Cassius and the rest of the "Republicans" would be better described as being the Publicani faction.

Under the circumstances, I'd have sided with Caesar and the populares. The establishment of the Principiate saved Rome from a decline comparable to that of the Hellenistic powers, or at least staved it off for a while. After that, I'd probably have backed Anthony rather than Octavian, for the same reason as Cleopatra VII: Lepidus was a non-entity and Octavian was seemingly on his deathbed when they returned to Italy after defeating Cassius and Brutus. Who would have thought the young blighter's health wasn't as fragile as it seemed?