Campaigner

Military.

military operations for a specific objective.
Obsolete. the military operations of an army in the field for one season.

a systematic course of aggressive activities for some specific purpose:
a sales campaign.
the competition by rival political candidates and organizations for public office.
to serve in or go on a campaign:
He planned to campaign for the candidate. He campaigned in France.
to race (a horse, boat, car, etc.) in a number or series of competitions.
Contemporary Examples

‘Tired’ Cain Campaign Slows Down Howard Kurtz October 27, 2011
Egypt’s Fractious Presidential Race Reflects a Country Deeply Divided Lauren Bohn June 13, 2012
‘Tricky Dick’ vs. the Pink Lady Sally Denton November 15, 2009
GOP-Backed Voter Fraud Laws Aim To Disenfranchise Students Jake Heller September 3, 2012
Mitt Romney’s Unfavorable Ratings Have Been Rising Since Iowa Andrew Romano January 31, 2012

Historical Examples

The Newcomes William Makepeace Thackeray
Frontier Boys in Frisco Wyn Roosevelt
Company G A. R. (Albert Rowe) Barlow
How to Travel Thomas W. Knox
Hereward, The Last of the English Charles Kingsley

noun
a series of coordinated activities, such as public speaking and demonstrating, designed to achieve a social, political, or commercial goal: a presidential campaign, an advertising campaign
(military) a number of complementary operations aimed at achieving a single objective, usually constrained by time or geographic area
verb
(intransitive) often foll by for. to conduct, serve in, or go on a campaign
n.
v.