The political plot of the prequel trilogy does bring to mind the Roman revolution--the transition from a republic to an empire but the political system in the movies (neither the galactic republic nor the empire) resembles Roman governments.

The Roman Republic (509-27ish BCE depending on who you ask) was essentially ruled by a Senate. The Senate was made of wealthy Roman citizens who had held elected office. The Senate acted as a deliberative body which guided the magistrates (quaestors, aediles, praetors, and consuls) who did the dirty work administrating the government (money, public works, justice, and "head of state" respectively). In contrast, the Galactic Senate seems to be more of a pariliament where there is a chancellor elected to rule the Republic from among the Senators. A further contrast is that the Senate is made of delegations from the planets that make up the Republic. The Roman Senate was not meant to represent the interests of all the peoples Rome ruled, just the best men of Rome.

The transition from Republic to Empire is also fairly similar though in Rome the lead up was more about political intrigue on the part of Caesar and later Octavian than it was about war like in Star Wars. In Rome, beginning in 52 BCE, there were riots and political disputes concerning Julius Caesar who had spent the last 6 years in Gaul and wanted to return to Rome and hold office (otherwise he would be open to prosecution by his political enemies, Roman politicians were extremely litigious at the time which often led to vacant magistracies and further disorder). The next few years were a little more stable. The revolt of Vercingetorix put the question of Caesar's return on hold and Pompey had brought a semblance of order to Rome after holding an unprecedented solo consulship in 52. Anyways in 49 BCE, Caesar was denied the possibility of running for office in abstentia and marched on Rome to defend his dignity and the dignity of the tribunes who protested the decisions of the Senate (tribunes were a special magistrate who held the power to veto the Senate and magistrates and call for popular votes). This led to civil war lasting from 49-45 BCE all around the Mediterranean. In 49, Caesar, upon his return to Rome, was declared dictator, an office used when the consuls were unable to perform their duties which gave one man the powers of the consuls. These intrigues and particularly the popular politics of all this is entirely absent from Star Wars (unless you consider the rebellion an aspect of this).

Caesar was famously murdered in 44 sparking another civil war between Caesar's partisans (Mark Antony and Octavian) and Caesar's assassins who were also magistrates (most notable Brutus and Cassius). In 43, before going to war with the assassins, Antony, Octavian, and a third man Lepidus were declared triumvirs in a popular vote. Essentially they were each made dictator of different regions of the Roman empire and they were elected with the specific mandtate (provincia in Latin) to restore order to the state (res publica in Latin). It is this moment which most resembles the creation of the Galactic Empire. The government, in the face of war, turns power over to a small group. By 32 BCE Octavian had successfully defeated the other two triumvirs and in 27 BCE he changed his name to Augustus, signalling the beginning of the Roman Empire. The transition was slow and perhaps Episode 4 shows some slowness too with the way Tarquin and Vader interact it seems that the Emperor does not hold authoritarian control just yet.

There is one more similarity in that the clone army is a privately raised army. The armies Octavian were levied by a person without imperium and Pompey had raised such an army in his youth. Likewise, Caesar, Antony, and Octavian kept armies beyond the scope on their imperium and raised armies from veteran soldiers, a pre-baked army similar to the clone army.

Likewise, there was resistance to the changing political system particularly in 44 BCE, but by the time Octavian defeated Antony at the Battle of Actium in 32 BCE, there was simply no person or region of the empire with enough political power or military strength to challenge him. Even regional revolts seem to have been minor (though these could be covered up in the surviving sources). The events/parties of Episode 7 do not seem to have a parallel in Roman history as far as I can surmise.

So the plot is vaguely similar but the political institutions portrayed in Star Wars are not similar to Roman examples. Where public support, rioting and activism (on the part of volunteering in unofficial armies) is absent from Star Wars, it was integral in the Roman Revolution. Likewise the peculiar mix/conflict of oligarchy and democracy in the Roman political system which led to the civil wars is also absent in Star Wars.

For further reading on the Roman Revolution I suggest:

Ronald Syme: The Roman Revolution. An oldie but goodie. Syme is heavily influenced by the rise of fascism in Europe and the death of his colleague Munzer in the German camps and gives a dense history of the reasons Rome was able and even willing to change from Republic to Empire.

P.A. Brunt: "The Army and the Land" and "The Fall of the Roman Republic" collected in The Fall of the Roman Rebulic and Related Essays. Brunt is very scholarly. Where Syme looks at the oligarchy at the top of Roman society, Brunt looks at the soldiers and the landed elite in these essays and attempts to answer why those groups went along with warring generals and Octavian.

A more narrative textbook is Scullard's Rome from Gracchi to Nero. He covers 200 years of Roman history here in textbook style, so it's a good place to start.

There is a lot. The empire in Star Wars is largely modeled on Nazi Germany: The costume design for the imperials was strongly inspired by fascist governments, the name "Stormtrooper" was taken from German paramilitary forces, "Vader" is the German word for "Father", and Lucas even referred to Imperial officers as Nazis during the filming. The Empire's institutions are somewhat based on the Roman empire (for example, it used to have a Senate, but it was disbanded in favor of greater executive power), while the Emperor himself was modeled on Richard Nixon according to Lucas.