Harry's one drawback, capturing the heart of citizens (6)
I believe the answer is:
wizard
'harry's one' is the definition.
(Harry Potter is a wizard)
'drawback capturing the heart of citizens' is the wordplay.
'drawback' becomes 'ward' (I've seen this in other clues).
'capturing' is an insertion indicator.
'the heart of' says to take the centre.
The middle of 'citizens' is 'iz'.
'ward' enclosing 'iz' is 'WIZARD'.
(Other definitions for wizard that I've seen before include "Great" , "One who can work wonders" , "software guide" , "Jolly good" , "Expert <" .)