One causes damage for political reasons (8)
I believe the answer is:
saboteur
'one causes damage for political reasons' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for saboteur that I've seen before include "One engaged in malicious disruption" , "Our beats (anag) - fifth columnist" , "One deliberately damages" , "One who wrecks" , "Political wrecker" .)