The Roman Republic “fell” with Julius Caesar but the Empire lived on for 4 centuries or so. I have a peeve with those who insist on comparing the present situation in the USofA with Decline And Fall of the Roman Empire. It is more like the end of the Republic and we don’t know yet if America will become Empire. One difference will be that the Romans did not lose a lot of day-to-day freedom. Our own transition to Empire is likely to be to a bureaucratic totalitarianism. We are already seeing economic Caesarism grabbing hold in great fistfuls with Paulson’s accession to Chancelorship.
I worry about the tyranny of the courts, as you refer to it, "Bureaucratic totalitarianism" and the state imposing standards in the private arena.
Obama's goon squads tell me everything I need to know about him.
I believe that you are correct about the earlier Empire, except for the Senatorial class, of course. Sometimes called the Principate (for 'First citizen', which is how the Emperor was designated), it lasted from Augustus up until the late third century, With Diocletian the idea that Rome was still a Republic disappeared, as the government, (the 'dominate') became ever more autocratic.
Lots of lefties, and even some supposed "conservatives," (i.e., Buchanan), claim the US is already an "empire." It's hogwash, of course, unless you redefine the word "empire" to mean what New Yorkers mean by "The Empire State" -- just a metaphor or school mascot, nothing to do with serious reality.
Yes, 100 years ago, the US had a real "empire," including the Philippines, Puerto Rico and some Pacific Islands, some of which remain part of the US today. But that's not what our critics are talking about.
Finally, we should note the word has long been used metaphorically, going back even to George Washington, who referred to the newly constituted thirteen United States as "our empire."
Point is: when we talk about an "American Empire," we need to be clear as to which sense of the word we mean.