Rabble-rouser having a go at it, suffering resistance (8)
I believe the answer is:
agitator
'rabble-rouser' is the definition.
(thesaurus)
'a go at it suffering resistance' is the wordplay.
'suffering' indicates an anagram.
'resistance' becomes 'r' (abbreviation).
'go'+'at'+'it'='goatit'
'goatit' with letters rearranged gives 'gitato'.
'a'+'gitato'+'r'='AGITATOR'
'having' acts as a link.
(Other definitions for agitator that I've seen before include "Organiser" , "one causing a stir" , "washing machine" , "A good mixer, maybe" , "cause of trouble" .)