Propagandist

(n.) A person who devotes himself to the spread of any system of principles.

Thesaurus Entries

agent provocateur, agitator, catalyst, demagogue, exciter, firebrand, fomenter, incendiary, inciter, indoctrination, inflamer, instigator, mischief-maker, propaganda, propagandism, propagandist, provocateur, provoker, rabble-rouser, ringleader, rouser, seditionary, seditionist, troublemaker, urger