Exile keeping unruly racists in order (9)
I believe the answer is:
ostracism
'exile' is the definition.
(I know that ostracism is a type of punitive banishment)
'unruly racists in order' is the wordplay.
'unruly' indicates anagramming the letters.
'in' is an insertion indicator.
'order' becomes 'om' (Order of Merit).
'racists' anagrammed gives 'stracis'.
'stracis' put within 'om' is 'OSTRACISM'.
'keeping' is the link.
(Other definitions for ostracism that I've seen before include "Exclusion from a group or society" , "Shunning" , "isolation" , "cold shoulder" , "Boycott" .)