δημαγωγός

Demagogue comes from Greek dēmagōgós — dêmos (people) + agōgós (leader, from ágein, to lead). In fifth-century Athens, the word was descriptive, not derogatory. A demagogue was anyone who led the demos — the common people — in the democratic Assembly. Pericles, the greatest Athenian statesman, was called a demagogue. The word did not imply manipulation. It implied democratic leadership.

The word's degradation began with Athenian intellectuals who distrusted popular rule. Thucydides described Cleon, a popular politician of the 420s BCE, as a demagogue in unflattering terms — loud, aggressive, appealing to the crowd's emotions rather than reason. Plato and Aristotle cemented the negative meaning: a demagogue was a leader who flattered the masses, told them what they wanted to hear, and used their power for personal gain. The philosopher's contempt for popular opinion was baked into the word.

English borrowed 'demagogue' in the 1640s, during the English Civil War, when parliamentary factions accused each other of demagoguery. The word has been used to describe populist politicians ever since: Huey Long, Joseph McCarthy, and countless others. The pattern is consistent: whoever uses the word 'demagogue' is claiming that a popular leader is manipulating the public. The accusation says as much about the accuser's view of the public as about the leader.

The word reveals an old tension in democratic theory. If the people choose a leader, and that leader tells them what they want to hear, is that democracy working or failing? Pericles and Cleon were both elected by the same Assembly. Athenian intellectuals called one a statesman and the other a demagogue. The difference was largely in who was doing the naming.