 At the January 1910 general election he worked as the election agent for Thomas Kettle.In 1923 Stewart was elected to the Dungannon Board of Governors, a post he held until the Board was dissolved in 1948.He was also elected to Tyrone County Council for the Nationalist Party, was a long-time member of Dungannon Urban District Council, and was the President of the Tyrone Ancient Order of Hibernians.