Echo vote at summit (4)
I believe the answer is:
apex
'summit' is the definition.
(I've seen this before)
'echo vote' is the wordplay.
'echo' becomes 'ape' (I've seen this in another clue).
'vote' becomes 'x' (how votes are marked).
'ape'+'x'='APEX'
'at' is the link.
(Other definitions for apex that I've seen before include "Summit - pinnacle" , "Point or summit" , "reasonable fare" , "Uppermost tip" , "crown" .)