The Cancer of Democracy

Bread and Circuses is the cancer of democracy, the fatal disease for which there is no cure. Democracy often works beautifully at first. But once a state extends the franchise to every warm body, be he producer or parasite, that day marks the beginning of the end of the state. For when the plebs discover that they can vote themselves bread and circuses without limit and that the productive members of the body politic cannot stop them, they will do so, until the state bleeds to death, or in its weakened condition the state succumbs to an invader--the barbarians enter Rome.

— Lazarus Long, in Robert Heinlein's To Sail Beyond the Sunset

(Note: To anyone who wants to nitpick - yes, I know that's from the cover of a paperback edition of Time Enough For Love, but it IS a depiction of Lazarus Long, so just stow it before you whine, all right?)