In part, Republican denies manoeuvring for the top job? (9)
I believe the answer is:
president
'the top job?' is the definition.
(I've seen this before)
'in part republican denies manoeuvring' is the wordplay.
'in' is an insertion indicator.
'part' becomes 'pt' (abbreviation).
'republican' becomes 'R' (political abbreviation).
'manoeuvring' indicates anagramming the letters.
'r'+'denies'='rdenies'
'rdenies' anagrammed gives 'residen'.
'pt' placed around 'residen' is 'PRESIDENT'.
'for' acts as a link.
(Other definitions for president that I've seen before include "Head of state of a republic" , "Head of a republic - or a club" , "Head of US company - tried pens (anag)" , "Celebrant" , "The chief executive of a republic" .)