May have power (5)
I believe the answer is:
might
This clue is a double definition.
'may' is the first definition.
('might' can be a synonym of 'may')
'power' is the second definition.
('might' can be a synonym of 'power')
'have' is the link.
(Other definitions for might that I've seen before include "Physical strength of old" , "What functions as an auxiliary" , "intensity of feeling" , "Doubtful" , "Capability" .)