Area's vote is for coalition (4)
I believe the answer is:
axis
'coalition' is the definition.
(axis is a kind of coalition)
'area's vote is' is the wordplay.
'area' becomes 'a' (maths abbreviation).
'vote' becomes 'x' (how votes are marked).
'a'+'x'+'is'='AXIS'
'for' is the link.
(Other definitions for axis that I've seen before include "where wheel turns?" , "Spindle - German/Italian alliance - deer" , "all revolves around this" , "Line about which to rotate" , "WW2 Nazi alliance" .)