"Becoming" memoirist Michelle (5)
I believe the answer is:
obama
'becoming memoirist michelle' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for obama that I've seen before include "Trump's predecessor" , "US presidential candidate" , "American president" , "President awarded the 2009 Nobel Peace Prize" , "44th US President" .)