Corrupt vote starts to unsettle troubled electorate (7)
I believe the answer is:
pollute
'corrupt' is the definition.
(thesaurus)
'vote starts to unsettle troubled electorate' is the wordplay.
'vote' becomes 'poll' (polling is a kind of voting).
'starts to' suggests taking the first letters.
The initial letters of 'unsettle troubled electorate' is 'ute'.
'poll'+'ute'='POLLUTE'
(Other definitions for pollute that I've seen before include "Taint, foul" , "Adulterate, contaminate" , "Add impurities" , "Make dirty or impure" , "Contaminate; defile" .)