WOW! Thanks for the link, mewzilla.
From your linked (Roman history) article …
Absolute imperial power replaced the complex check-and-balance system of the republic. The famous Senate declined from a vigorous state council, filled with civilian and military executives, into an ornamental rich men’s club. The Roman populace was no longer in a mood to fight for its constitutional liberties; it was lulled to sleep by the time-honored method: Panem et circenses. So long as it received free food at public expense, and elaborate games and spectacles, it ceased to concern itself with public affairs.
Private initiative disappeared; more and more the all-powerful imperial government was expected to look after everyone and attend to everything.