Spoilt broadcast supporting independent politician (8)
I believe the answer is:
impaired
'spoilt' is the definition.
('impair' can be a synonym of 'spoil')
'broadcast supporting independent politician' is the wordplay.
'broadcast' becomes 'aired' ('aired' can be a synonym of 'broadcast'**).
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'independent' becomes 'i'.
'politician' becomes 'mp'.
'i'+'mp'='imp'
'aired' put after 'imp' is 'IMPAIRED'.
(Other definitions for impaired that I've seen before include "Defective" , "casued damage" , "Hampered" , "Had negative impact" , "handicapped" .)