As a crossword puzzle clue, a career campaigner is a "POL."
In politics, it could refer to a politician, even one who has been elected to an office, who seems to never stop campaigning.
John Button - campaigner - was born in 1944.
Sam Thomas - campaigner - was born in 1986.
Sandra Brown - campaigner - was born in 1949.
Anthony Bailey - interfaith campaigner - was born in 1970.
Gordon Wilson - peace campaigner - was born on 1927-09-25.
Gordon Wilson - peace campaigner - died on 1995-06-27.
The cast of The Campaigner - 2012 includes: Joyce Brand as Joyce Brand
Donald Mackay - anti-drugs campaigner - died on 1977-07-15.
Donald Mackay - anti-drugs campaigner - was born on 1933-09-13.
Candidate?
Candidate
yes