Forgetting the fate of the Gracchi, the gang warfare between Clodius and Milo, etc., are we?

Not really, Aulus. The fates of the Gracchi were the first cracks in the foundation and represented a dramatic departure from politics as usual. It scared even those who disagreed with them, and there was a whole lot of foot-shuffling and turning a blind eye.

Milo and Clodius were a further development of the decay, but they were still an adjunct to senatorial debate. One engaged in dignified argument in the senate and then sent out one’s thugs later for a spot of intimidation. And, yes, there are plenty of other examples – armed gladiators outside the senate house, Sulla’s slaughter of captives where the senate could hear, etc. – but up to sometime between Caesar’s dictatorship and the rise of the second triumvirate, they could still pretend that things were the way they always had been. By the time of the Philippics, even the blindest, most self-absorbed optimate could see that the Republic was dead and the warlords were calling the shots, with or without the senate. And any senator rash enough to openly oppose the will of Antony was going to meet a messy end.