Republican in training not yet a lawyer (8)
I believe the answer is:
attorney
'lawyer' is the definition.
(I know that lawyer can be written as attorney)
'republican in training not yet a' is the wordplay.
'republican' becomes 'R' (abbreviation).
'in' is an insertion indicator.
'training' is an anagram indicator (to train can mean to grow something into a shape).
'not'+'yet'+'a'='notyeta'
'notyeta' is an anagram of 'attoney'.
'r' going into 'attoney' is 'ATTORNEY'.
(Other definitions for attorney that I've seen before include "Any torte (anag.)" , "profession" , "Lawman" , "Advocate" , "Porter's first employer's occupation" .)