There are so many ways to approach the Republic, but one of the ones that made a big impression on me when I first read about it, years ago, is that the Roman establishment - and probably the proles too, come to think about it - had an almost religious veneration for the achievements of the ancestors and became very rigid in their outlook about change. Change was BAD (that's sooooooooooo not the way we look at life, since the Renaissance, but there you are...) Any dickering with the mos maoirum had potentially lethal consequences. In a way, I can understand that - my kneejerk reaction, for example, when any politician says to amend the constitution for any (passing) political issue, is "don't do it" because I have great faith in the constitution. They must have felt the same way, although it was tradition rather than one written document they venerated. But then you get ridiculous issues like the fuss Cato Uticensis made over some changes to - was it the Basilica Sempronia? - where some demmed fool column was smack in the way of the increasing crowds doing business there. The Senate voted to remove the column but Cato went on a one-man sit-down strike against it - his grandfather, Cato the Censor, had put it up, that made it part of the mos maoirum, it could not be removed. (Symbolic of a lot of Cato's thinking, IMHO). Everyone caved, and the column remained - still smack in everybody's way.

But then you get the situation where the empire has exploded, the stresses on Rome have gone up by several powers, the old ways no longer fit the new conditions - but STILL you can't change things if it's not how the ancestors saw it, 400 years before. That made a pressure cooker of politics in those decades, explosions were inevitable.