Liberal in sham pledge (5)
I believe the answer is:
ample
'liberal' is the definition.
(I've seen this before)
'in sham pledge' is the wordplay.
'in' says the answer is hidden in the clue.
'AMPLE' is hidden within 'sham pledge'.
(Other definitions for ample that I've seen before include "Plentiful; capacious" , "Fully enough" , "Large enough" , "Plenty, more than enough" , "Big" .)