Winger in communist vote (7)
I believe the answer is:
redpoll
'winger' is the definition.
(redpoll is a kind of bird)
'communist vote' is the wordplay.
'communist' becomes 'red' (red is a kind of communist).
'vote' becomes 'poll' (polling is a kind of voting).
'red'+'poll'='REDPOLL'
'in' is the link.
(Other definitions for redpoll that I've seen before include "Bird" , "Flyer" , "cow" , "finch" .)