Voter let core be destroyed (7)
I believe the answer is:
elector
'voter' is the definition.
(I know this)
'let core be destroyed' is the wordplay.
'be destroyed' indicates an anagram.
'let'+'core'='letcore'
'letcore' anagrammed gives 'ELECTOR'.
(Other definitions for elector that I've seen before include "One crossing" , "Constituent" , "might he make one cross?" , "Citizen with a right to vote" , "One may make one cross" .)