Harry perhaps inspiring Liberal conspirator (7)
I believe the answer is:
plotter
'conspirator' is the definition.
(I know that conspirator can be written as plotter)
'harry perhaps inspiring liberal' is the wordplay.
'harry perhaps' becomes 'Potter' (Harry Potter).
'inspiring' indicates putting letters inside.
'liberal' becomes 'l' (abbreviation).
'potter' placed around 'l' is 'PLOTTER'.
(Other definitions for plotter that I've seen before include "Conspirator" , "Schemer" , "One who schemes" , "Conspirator's" .)