The Collaborative International Dictionary of English v.0.48:

equalitarianism \equalitarianism\ n.
   the doctrine of the equality of mankind and the desirability
   of political and economic and social equality.

   Syn: egalitarianism.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

equalitarianism
    n 1: the doctrine of the equality of mankind and the
         desirability of political and economic and social equality
         [syn: egalitarianism, equalitarianism]