1) Activist 2) Advocate 3) Candidate 4) Champion 5) Dissenter 6) Militant 7) Nominee 8) Objector 9) Party man in action 10) Party worker 11) Person on a trail 12) Political leader 13) Politician 14) Politician, periodically 15) Politico 16) Protester 17) Supporter 1) Activist 2) Candidate 3) Electioneer 4) Nominee 5) Petitioner 6) Pol 7) Protester 8) Spoiler 9) Supplicant 10) Supporter 
• (n.) One who has served in an army in several campaigns; an old soldier; a veteran.
Cam·paign'er noun One who has served in an army in several campaigns; an old soldier; a veteran. 
[n] - a politician who is running for public office
candidate 1 nominee noun a politician who is running for public office