Career
Mills ran for a seat to the Alberta Legislature in a by-election held in the Athabasca electoral district on June 3, 1920. He stood as the Liberal candidate in a straight fight against former Modern Language Association and Independent candidate James Cornwall. Mills ran for a second term a year later in the 1921 general election.
Mills was projected to be returned unopposed, however Conservative candidate John Angelo filed nomination papers at the last minute.
Mills was returned with a landslide. The run up to the 1926 Alberta general election saw tension increase between Mills and the Liberal party.
The Liberal executive scrapped and re-called the meeting for May 28, 1926. Mills instead ran for re-election as an Independent Liberal and was defeated finishing last in a hotly contested race that went to ballot transfers.