He was a Progressive Conservative member of the Legislative Assembly of Ontario from 1995 to 1999, and served as a cabinet minister in the government of Mike Harris.
He took part in fundraising activities for several municipal, provincial and federal campaigns for such figures as Brian Mulroney, Joe Clark, David Crombie and Art Eggleton, and was the financial comptroller for the Progressive Conservative Party of Canada's national election campaigns in 1984 and 1988.
He ran in the riding of Eglinton in the 1995 provincial election, and defeated Liberal incumbent Dianne Poole by about 4,500 votes.
[1] On June 26, 1995, he was appointed as Minister of Economic Development, Trade and Tourism in the first cabinet of Mike Harris.
[5] In 2000, Saunderson and his wife established a research chair at the University of Toronto to facilitate studies in brain injuries.