WordNet (r) 3.0 (2006):

rightist
    adj 1: believing in or supporting tenets of the political right
           [syn: rightist, right-wing]
    n 1: a member of a right wing political party [syn: rightist,
         right-winger]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "rightist":
   Bircher, Bourbon, Tory, bitter-ender, conservationist,
   conservatist, conservative, diehard, extreme right-winger, fogy,
   fundamentalist, hard hat, imperialist, laudator temporis acti,
   monarchist, mossback, old fogy, old liner, old school,
   radical right, reactionarist, reactionary, reactionist, right,
   right wing, right-winger, royalist, social Darwinist, standpat,
   standpatter, stick-in-the-mud, tory, ultraconservative