exponent vs protagonist

Other hyponyms of exponent include apologist, justifier, vindicator, commie, communist, constitutionalist, Darwinian, democrat, populist, fascist, federalist, Gnostic, humanist, humanitarian, ideologist, ideologue, internationalist, irredentist, irridentist, isolationist, Jansenist, libertarian, Maoist, Marxist, nationalist, neoclassicist, neutralist, nullifier, drumbeater, partisan, zealot, partitionist, Platonist, pro-lifer, presenter, sponsor, protectionist, republican, ritualist, ruralist, secessionist, secularist, separationist, separatist, interpreter, representative, spokesperson, voice, suffragist, admirer, booster, champion, friend, supporter, supremacist, teleologist, Thatcherite, unilateralist, voice in the wilderness.