WordNet (r) 3.0 (2006):

pull strings
    v 1: influence or control shrewdly or deviously; "He manipulated
         public opinion in his favor" [syn: manipulate, pull
         strings, pull wires]

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "pull strings":
   act on, angle, approach, bear upon, contrive, draw, draw on,
   engineer, exert influence, finagle, gerrymander, get cozy with,
   intrigue, jockey, lead on, lobby, lobby through, machinate,
   magnetize, make advances, make overtures, make up to, maneuver,
   manipulate, play games, plot, scheme, wangle, wire-pull, work on