Turn the following verbs into nouns denoting the doer of the action. to support; to vote; to manufacture; to own; to oppose; to believe; to elect; to win; to defend; to direct; to represent; to preside.

supporter
voter
manufacturer
owner
oppositionist (или opposer)
believer
elector
winner
defender
director
representative
president

To support - supporter
to vote - voter
to manufacture - manufacturer 
to own - owner
to oppose - oppositionist
to believe - believer
to elect - elector
to win - winner
to defend - defender
to direct - director
to represent - representative 
to preside - president