I don't think you can possibly overestimate the tensions between the optimates and any man, like Augustus, who was setting up one-man rule. At the same time, you can't overestimate the importance of the fact that so many of the former leaders of the Republic - those great families that had run the Republic like their own private fiefdoms for many decades - were now dead, impoverished through proscriptions, or in exile.

Nor can you overestimate the fact that, unlike Caesar, Octavian came to rule from a family without any Optimate pretensions, with a country rather than Roman background, and that he was adopted by a man many had come to loathe.

All in all, to me it's a flat miracle that Augustus was able to sashay his way, ever so gently, into a position of not only absolute power, but absolute power that restored order. It's like looking at the French Revolution. For all its violence, by the time it was over, hundreds of thousands - millions - of poverty-stricken Frenchmen who had been permitted no stake at all in the country, had risen to quiet middle-class involvement. Similarly, by the time Augustus died, the true revolution had been carried out by who actually ran the Empire, and the nobles were firmly muzzled and incorporated into a system that also allowed provincials, freedmen, equestrians, and thousands of non-classy people into the maintenance and interest of the Roman state.