Alexander Fraser Tyler from "Cycle of Democracy":
A democracy cannot exist as a permanent form of government. It can only exist until the voters discover that they can vote themselves largesse from the public treasury. From that moment on, the majority always votes for the candidates promising the most benefits the public treasury with the result that a democracy always collapses over lousy fiscal policy, always followed by a dictatorship. The average of the world's great civilizations before they decline has been 200 years. These nations have progressed in this sequence: From bondage to spiritual faith; from faith to great courage; from courage to liberty; from liberty to abundance; from abundance to selfishness; from selfishness to complacency; from complacency to apathy; from apathy to dependency; from dependency back again to bondage.Link. This is most likely the quote that John over at Power Line is referring to.