Hoorah for my degree! (er, the one I'm presumably going to have in 3 years' time) That was Juvenal, in his satire #10... "A body that used to confer commands, legions, rods and everything else, has now narrowed its scope, and is eager and anxious for two things only: bread and races." Circenses being the latin that can refer to a race or a circus (because of the arena, which was a circuit). Of course.
I can't think of Juvenal without recalling the programme that was on TV about him a few years ago. It consisted primarily of Stephen Fry wandering the crowded streets of London in a toga, scowling at everything. Personally I think that anything that brings that about has to be a good thing.