Head off and tear after the supporter (8)
I believe the answer is:
adherent
'the supporter' is the definition.
(I've seen this in another clue)
'head off and tear' is the wordplay.
'off' is an anagram indicator.
'and' is a charade indicator (letters next to each other).
'tear' becomes 'rent' (rent is a kind of tear).
'head' with letters rearranged gives 'adhe'.
'adhe'+'rent'='ADHERENT'
'after' is the link.
(Other definitions for adherent that I've seen before include "Weep" , "Sticking; partisan" , "Follower, partisan" , "supporter of party" , "Devotee" .)