Exploit voting procedure, producing one-sided document (4,4)
I believe the answer is:
deed poll
'one-sided document' is the definition.
(legal document made by a single party)
'exploit voting procedure' is the wordplay.
'exploit' becomes 'deed' (synonyms).
'voting procedure' becomes 'poll'.
'deed'+'poll'='DEED POLL'
'producing' acts as a link.
(Other definitions for deed poll that I've seen before include "I confirm new designation" , "Legal document made and executed by one party only" , "means to change name" , "Legal action by one person, to change their name perhaps" , "Means of changing name" .)