Demagogue

demagogue
    n 1: a political leader who seeks support by appealing to
         popular passions and prejudices [syn: {demagogue},
         {demagog}, {rabble-rouser}]
    

Demagogue \Dem"a*gogue\ (?; 115), n. [Gr. dhmagwgo`s a popular
   leader; commonly in a bad sense, a leader of the mob; dh^mos
   the people + 'agwgo`s leading, fr. 'a`gein to lead; akin to
   E. act: cf. F. d['e]magogue.]
   A leader of the rabble; one who attempts to control the
   multitude by specious or deceitful arts; an unprincipled and
   factious mob orator or political leader.
   [1913 Webster]
    

56 Moby Thesaurus words for "demagogue":
      agent provocateur, agitator, agitprop, catalyst, debate, debater,
      declaim, declaimer, elocute, exciter, firebrand, fomenter,
      harangue, haranguer, hold forth, hothead, incendiary, inciter,
      inflamer, instigator, jawsmith, mischief-maker, mouth, orate,
      out-herod Herod, panelist, perorate, provocateur, provoker,
      public speaker, rabble-rouse, rabble-rouser, rant, ranter, read,
      recite, ringleader, rodomontade, rouser, seditionary, seditionist,
      speaker, speecher, speechifier, speechmaker, spiel, spieler,
      spokesman, spokeswoman, spout, spouter, talker, troublemaker,
      tub-thump, tub-thumper, urger