What they were doing before they became leader, and then, PM by winning at least one election.
* if they only won a minority.
Harper - Leading the pro-business NCC
Martin - being Finance minister*
Chretien - Working in business, at
The Brick (no really)Mulroney - Big-time businessman.
Trudeau - being in Cabinet
Pearson - Saving the world*
(according to the Nobel Peace people), also in Cabinet
Diefenbaker - Lawyer, MP, and repeated political loser
St. Laurent - In Cabinet
King - Labour Negotiator, Lecturer (on circuit), Industrial Researcher
Borden - Businessman
Laurier - In Cabinet, MP
Mackenzie - MP, Media mogul
Macdonald - Premier of Canada, and before that, MP.