Dissenter sure can't change (8)
I believe the answer is:
recusant
'dissenter' is the definition.
(recusant is a kind of dissenter)
'sure can't change' is the wordplay.
'change' indicates an anagram.
'sure'+'cant'='surecant'
'surecant' with letters rearranged gives 'RECUSANT'.
(Other definitions for recusant that I've seen before include "Nonconformist" , "refusing to toe the line" , "One refusing to comply, submit" , "not submitting to authority" , "Confused Etruscan who refuses to obey authority" .)