Career
Thomson first ran for the leadership of the Ontario Liberal Party in 1943 but came in fourth place losing to Harry Nixon. He was first elected to the Canadian House of Commons in the 1949 federal election.
Thomson first ran for the leadership of the Ontario Liberal Party in 1943 but came in fourth place losing to Harry Nixon. He was first elected to the Canadian House of Commons in the 1949 federal election.
In 1950, he left federal politics and ran again for the leadership of the Ontario Liberal Party and won, defeating social reformer Harry Cassidy. He remained leader of the party for another three years due to its state of disorganization, and was replaced by Farquhar Oliver in 1954.