 He also served as chairman of the Quebec Conservative Association in 1949, 1953 and 1957 and as first vice-president of the Progressive Conservative Party of Canada in 1955 and was the only French Canadian to support John Diefenbaker's candidacy to lead the Progressive Conservatives at their 1956 leadership convention.The Conservatives took power following the 1957 federal election and Diefenbaker, as prime minister, had Drouin appointed to the Senate of Canada on October 4, 1957 and named him Speaker of the Senate despite his lack of parliamentary experience.During his tenure he served as joint-president of the Commonwealth Parliamentary Association, chairman of the Canada-NATO Parliamentary Association and the chairman of the Canada-United States Interparliamentary Association.