Dickens on the power of demagoguery in Barnaby Rudge.  Interesting that Dickens is writing in 1840 about how leaders in 1780 who unscrupulously pervert the will of the ignorant masses and in 2012 it is still all too true:

To surround anything, however monstrous or ridiculous, with an air of mystery, is to invest it with a secret charm, and power of attraction which to the crowd is irresistible. False priests, false prophets, false doctors, false patriots, false prodigies of every kind, veiling their proceedings in mystery, have always addressed themselves at an immense advantage to the popular credulity, and have been, perhaps, more indebted to that resource in gaining and keeping for a time the upper hand of Truth and Common Sense, than to any half-dozen items in the whole catalogue of imposture. Curiosity is, and has been from the creation of the world, a master-passion. To awaken it, to gratify it by slight degrees, and yet leave something always in suspense, is to establish the surest hold that can be had, in wrong, on the unthinking portion of mankind.

If a man had stood on London Bridge, calling till he was hoarse, upon the passers-by, to join with Lord George Gordon, although for an object which no man understood, and which in that very incident had a charm of its own,—the probability is, that he might have influenced a score of people in a month. If all zealous Protestants had been publicly urged to join an association for the avowed purpose of singing a hymn or two occasionally, and hearing some indifferent speeches made, and ultimately of petitioning Parliament not to pass an act for abolishing the penal laws against Roman Catholic priests, the penalty of perpetual imprisonment denounced against those who educated children in that persuasion, and the disqualification of all members of the Romish church to inherit real property in the United Kingdom by right of purchase or descent,—matters so far removed from the business and bosoms of the mass, might perhaps have called together a hundred people. But when vague rumours got abroad, that in this Protestant association a secret power was mustering against the government for undefined and mighty purposes; when the air was filled with whispers of a confederacy among the Popish powers to degrade and enslave England, establish an inquisition in London, and turn the pens of Smithfield market into stakes and cauldrons; when terrors and alarms which no man understood were perpetually broached, both in and out of Parliament, by one enthusiast who did not understand himself, and bygone bugbears which had lain quietly in their graves for centuries, were raised again to haunt the ignorant and credulous; when all this was done, as it were, in the dark, and secret invitations to join the Great Protestant Association in defence of religion, life, and liberty, were dropped in the public ways, thrust under the house-doors, tossed in at windows, and pressed into the hands of those who trod the streets by night; when they glared from every wall, and shone on every post and pillar, so that stocks and stones appeared infected with the common fear, urging all men to join together blindfold in resistance of they knew not what, they knew not why;—then the mania spread indeed, and the body, still increasing every day, grew forty thousand strong.