Declares the fellow to be a top politician (9)
I believe the answer is:
statesman
'a top politician' is the definition.
'statesman' can be an answer for 'politician' (statesman is a kind of politician). I am not sure about the 'a top' bit.
'declares the fellow' is the wordplay.
'declares' becomes 'states' (I've seen this in another clue).
'the fellow' becomes 'man' (fellow can mean a man).
'states'+'man'='STATESMAN'
'to be' is the link.
Can you help me to learn more?
(Other definitions for statesman that I've seen before include "Experienced politician" , "Distinguished politician" , "Respected politician" , "Eminent politician" , "Political leader" .)