Political fanatics unfit, clearing off (7,6)
I believe the answer is:
lunatic fringe
'political fanatics' is the definition.
(I've seen this before)
'unfit clearing off' is the wordplay.
'off' is an anagram indicator.
'unfit'+'clearing'='unfitclearing'
'unfitclearing' is an anagram of 'LUNATIC FRINGE'.
(Other definitions for lunatic fringe that I've seen before include "Extreme party members" , "Fanatical element" , "Extreme fanatics" , "Extreme members of group" , "People who support extreme views" .)