Fool expected to seize power (4)
I believe the answer is:
dupe
'fool' is the definition.
('dupe' can be a synonym of 'fool')
'expected to seize power' is the wordplay.
'expected' becomes 'due' (I've seen this before).
'to seize' is an insertion indicator.
'power' becomes 'p'.
'due' going around 'p' is 'DUPE'.
(Other definitions for dupe that I've seen before include "A cat's-paw" , "Gull" , "Deceive, trick" , "Victim of deceit or fraud" , "Deceive, make fool of" .)