by: Franz Ferdiand
A demagogue /ˈdɛməɡɒɡ/ (from Greek δημαγωγός, a popular leader, a leader of a mob, from δῆμος, people, populace, the commons + ἀγωγός leading, leader) or rabble-rouser is a leader in a democracy who gains popularity by exploiting prejudice and ignorance among the common people, whipping up the passions of the crowd and shutting down reasoned deliberation. Demagogues have usually advocated immediate, violent action to address a national crisis while accusing moderate and thoughtful opponents of weakness or disloyalty. Demagogues overturn established customs of political conduct, or promise or threaten to do so. Most who were elected to high office changed their democracy into some form of managed democracy.
Demagogues have appeared in democracies since ancient Athens. They exploit a fundamental weakness in democracy: because ultimate power is held by the people, nothing stops the people from giving that power to someone who appeals to the lowest common denominator of a large segment of the population. –Wikipedia