campaigner

/kæmˈpeɪnər/
noun
  1. A person who takes part in an organized effort to achieve a social or political goal.
    • Veteran campaigners know that persistence is key to winning support.
    • The campaigner knocked on hundreds of doors to talk to voters.
    • She is a dedicated campaigner for environmental protection.
  2. A person who runs for a political office or works on a political campaign.
    • As a seasoned campaigner, he knew how to connect with different audiences.
    • The young campaigner was nervous before her first debate.
    • The campaigner gave a passionate speech at the town hall.