Did Romans recognise the fall of the republic?

[AureliusFalco]

SiginiferOne wrote:
Can you provide anything other than conjecture?

Unfortunately I cannot find a quote or source that mentions a member of one of the great families of the Republic speaking down to an Emperor. However the fact that a few such men(such as Faustus Cornelius Sulla or Gnaeus Cornelius Cinna Magnus) did try to overthrow or kill Augustus would seem to me that they didn't consider him worthy of rule i.e. a social inferior.

SiginiferOne wrote

Of course they weren't "in power", they were freely elected or disgraced and taken from the rostrum. How is that being 'in power'? How did the Senatorial privileges under the Principate, including governorship of provinces, vast incomes, consulships with the Emperor and many such things, constitute not being in power

How is being an elected magistrate of Rome not power? Consuls, proconsuls, praetors and other positions like those could control vast amounts of men, deal with foreign rulers on equal terms and even interfere in foreign wars. And even when there terms were up they were still regarded as great and powerful men,able to influence the Senate and Assembly.
Under the the Principate, all that power(which I admitted was still great) was still owed to the Emperor. If he didn't want you to advance,it was unlikely that you would. You owed your power and prestige to the ruler.
I admit that the neither Helvidius Priscus or Musonius Rufus came from great Senatorial families (although Priscus' father-in-law,Publius Clodius Thrasea Paetus did). And couldn't Cornuntus simply be echoing Brutus,who also called Cassius "the Last of the Romans"?
And finally I don't know how much I trust the Historia Augusta, and even then the quote doesn't prove Avidius Cassius wanted to restore the republic.