Davidson joined the Co-operative Commonwealth Federation (CCF) in 1934 after meeting J.S. Woodsworth. She remarked about him, "He had a burning fire of love for people. You could warm your hands in his personality." She worked for Agnes MacPhail and Arthur Williams on their election campaigns in the 1930s. She ran for the CCF in the 1953 federal election in the riding of York East coming third behind Robert McGregor. She also ran provincially in the 1955 Ontario election against Hollis Beckett, again with a poor showing. In 1971 she recalled this period of involvement with the CCF. She said, "I'm not a partisan politician at all ... I ran for the CCF 15 or 16 years ago when the CCF had fallen on very stony places. I don't know why I ran. I had no thought of winning."