Unfit! Clearing out extremists in party (7,6)
I believe the answer is:
lunatic fringe
'extremists in party' is the definition.
'lunatic fringe' can be an answer for 'extremists' (I've seen this in another clue). I am unsure of the 'in party' bit.
'unfit clearing out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'unfit'+'clearing'='unfitclearing'
'unfitclearing' anagrammed gives 'LUNATIC FRINGE'.
Can you help me to learn more?
(Other definitions for lunatic fringe that I've seen before include "Eccentric minority" , "Barmy extremists" , "Fanatical element" , "Extreme political element" , "Most extreme members of an organisation" .)