During the Great Depression, as a Baptist preacher, Douglas watched his parishioners suffer. Looking for ways to alleviate their suffering, he made an unsuccessful run for the provincial candidacy for the Farmer-Labour Party. He became a Member of Parliament for the Cooperative Commonwealth Federation. In 1944, Douglas became the Premier of Saskatchewan, leading the first democratic socialist government in North America.
In 1947, Premier Douglas brought in hospital insurance in Saskatchewan, the first province to do so. In 1960, the CCF was renamed the New Democratic Party with Douglas as its leader. Two years later, Saskatchewan's Medical Care Insurance Act came into effect, thanks in large part to the groundwork set by former Premier Douglas. Ontario did not get equivalent care until 1972, due in large part to resistance from Premier Robarts.