Idiot raised money, supported by comic (6)
I believe the answer is:
nitwit
'idiot' is the definition.
(I've seen this before)
'raised money supported by comic' is the wordplay.
'raised' is a reversal indicator (going up in a down clue).
'money' becomes 'tin' (old-fashioned slang term for money).
'supported by' says to put letters next to each other (in a down clue, some letters hold up others).
'comic' becomes 'wit' (a witty person).
'tin' backwards is 'nit'.
'nit'+'wit'='NITWIT'
(Other definitions for nitwit that I've seen before include "Informally a stupid person, like funny flea?" , "Birdbrain" , "Plonker" , "Turkey" , "Silly fool" .)