Debate smashing icons with radical backing (8)
I believe the answer is:
consider
'debate' is the definition.
(I know that debate can be written as consider)
'smashing icons with radical backing' is the wordplay.
'smashing' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'radical' becomes 'red' (red can mean a communist).
'backing' says the letters should be written in reverse.
'red' written backwards gives 'der'.
'icons' is an anagram of 'consi'.
'consi'+'der'='CONSIDER'
(Other definitions for consider that I've seen before include "Attend to" , "Hold" , "Deliberate" , "Suppose" , "Cogitate" .)