Attackers of Republican supporters (7)
I believe the answer is:
raiders
'attackers' is the definition.
'republican supporters' is the wordplay.
I cannot quite understand how this works, but
'republican' could be 'r' (abbreviation in US politics) and 'r' is found within the answer.
The remaining letters 'aiders' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Other definitions for raiders that I've seen before include "' - - of the Lost Ark'" , "Marauding attackers" , "Attacking force" , "Marauders" .)