Support whip getting violent reaction (8)
I believe the answer is:
backlash
'violent reaction' is the definition.
(I've seen this before)
'support whip getting' is the wordplay.
'support' becomes 'back' (to back is to support or endorse).
'whip' becomes 'lash' (synonyms).
'getting' says to put letters next to each other.
'back'+'lash'='BACKLASH'
(Other definitions for backlash that I've seen before include "Violent reaction to event, like reverse whip" , "negative comments?" , "Repercussion" , "Provoked adverse reaction" , "Sudden violent reaction to an action or situation" .)