From 1944 to 1946, Grube was the President of the Ontario Co-operative Commonwealth Federation's (CCF) executive, often acting as the public spokesperson for the party after its leader, Ted Jolliffe, lost his seat in the Ontario general election on 4 June 1945. He also ran unsuccessfully several times for the House of Commons seat in what was then known as the Broadview electoral district during the 1940s.
