THESAURUS
extremist
Bolshevik, Fabian, Jacobin, Wobbly, agitator, anarchist, anarchistic, anarcho-syndicalist, bigoted, brawler, extravagant, extreme, extreme left-winger, extremistic, fanatic, frondeur, haggard, inordinate, insubordinate, insurgent, insurrectionary, insurrectionist, insurrecto, irrational, left-wing
extremist, lunatic fringe, malcontent, maverick, meliorist, mild radical, mildly radical, mutineer, nihilist, nihilistic, nonconformist, overenthusiastic, overreligious, overzealous, parlor Bolshevik, parlor pink, perfervid, pink, pinko, progressionist, progressist, progressive, progressivist, rabid, radical, rebel, red, reformer, reformist, revisionist, revolter, revolutional, revolutionary, revolutionist, rioter, sans-culotte, subversive, syndicalist, traitor, ultra, ultraconservative, ultraist, ultraistic, ultrazealous, unreasonable, utopian, utopist, wild-eyed, wild-looking, yippie, zealotic