Writer could become Trump's oracle (6,6)
I believe the answer is:
marcel proust
'writer' is the definition.
(Marcel Proust is an example)
'become trump's oracle' is the wordplay.
'become' indicates anagramming the letters.
'trumps'+'oracle'='trumpsoracle'
'trumpsoracle' anagrammed gives 'MARCEL PROUST'.
'could' is the link.
(Other definitions for marcel proust that I've seen before include "novelist" , "Corrupt males (anag) -- French author" .)