It was only natural that a woman so actively involved in the social issues of the day should take an interest in politics. Yet, as an idealist, Loise McKinney found much to object to in the world of politics.

Liquor and brewing companies contributed heavily to both major parties of the day, much to the displeasure of this Woman's Christian Temperance Union (WCTU) activist, who suspected their donations bought political influence. Thus, when the Non-Partisan League (NPL) joined Alberta's political landscape, McKinney welcomed it enthusiastically. It seems the feeling was mutual, for she was persuaded to run for election as a League candidate in the 1917 provincial election (the first provincial election in which women were allowed to run for office or vote). Somewhat to her own surprise, she was elected (as was Nursing Sister Roberta MacAdams).

Perhaps as a result of her innumerable speaking engagements on behalf of the WCTU, McKinney quickly developed a reputation for her skill as a debater.

Although she took an interest in making government prohibition legislation more effective, and in legislation to "aid" the "feeble-minded," her major project was to draft a bill regarding Dower rights. Together, she and Henrietta Muir Edwards drafted a document, which Louise McKinney introduced to the legislature. It was passed and became known as the "Dower Act."

Although she ran for re-election, McKinney was defeated—possibly due to changing public sentiment regarding prohibition. Despite retiring from active politics, she retained an interest in political issues—small wonder that she was one of the four Alberta women whom Emily Murphy invited to join her as petitioners in the Persons' Case.