middle-of-the-roader

from The Collaborative International Dictionary of English v.0.48

middle-of-the-road \middle-of-the-road\ adj.
   1. supporting or pursuing a course of action that is neither
      liberal nor conservative.

   Syn: centrist, moderate.
        [WordNet 1.5]

   2. not extreme, especially in political views.
      [WordNet 1.5] -- {middle-of-the-roader}, n. --
      {middle-of-the-roadism}, n.