The Collaborative International Dictionary of English v.0.48:

Priestcraft \Priest"craft`\, n.
   Priestly policy; the policy of a priesthood; esp., in an ill
   sense, fraud or imposition in religious concerns; management
   by priests to gain wealth and power by working upon the
   religious motives or credulity of others.
   [1913 Webster]

         It is better that men should be governed by priestcraft
         than by violence.                        --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

priestcraft
    n 1: a derogatory reference to priests who use their influence
         to control secular or political affairs
    2: the skills involved in the work of a priest