Liberal candidate finally left a vague flyer (7)
I believe the answer is:
leaflet
'flyer' is the definition.
(I've seen this in another clue)
'liberal candidate finally left a vague' is the wordplay.
'finally' indicates one should take the final letters.
'vague' indicates an anagram.
The last letters of 'liberal candidate' are 'le'.
'left'+'a'='lefta'
'lefta' is an anagram of 'aflet'.
'le'+'aflet'='LEAFLET'
(Other definitions for leaflet that I've seen before include "Pamphlet or booklet" , "very little greenery" , "Small information sheet" , "Distribute small circulars" , "It may advertise" .)