A republican has fully developed framework (8)
I believe the answer is:
armature
'framework' is the definition.
(I've seen this in another clue)
'a republican has fully developed' is the wordplay.
'republican' becomes 'R' (abbreviation in US politics).
'has' is a charade indicator (letters next to each other).
'fully developed' becomes 'mature' (I've seen this in another clue).
'a'+'r'+'mature'='ARMATURE'
(Other definitions for armature that I've seen before include "keeper" , "Part of dynamo" , "Rotating coils of an electric motor" , "Rotating dynamo coil - a rum tear (anag)" , "motor part" .)