I compare arguments mobilized for and against a policy to publicly fund private schools, including religious private schools, in Alberta and Ontario, Canada, and highlight how the arguments reflect each province's historical, ideological, and social contexts. Grounded in Maarten Hajer's argumentative discourse theory and based on findings from argumentative discourse analyses of 275 media articles, submissions to nine parliamentary committee meetings, and 14 interviews, I show how actors with disparate interests and values formed discourse coalitions as they pursued their policy preference by mobilizing one of two storylines: (1) "public funds are for public schools" or (2) "private schools deserve public funds." The findings demonstrate that policy supporters and opponents mobilized the same arguments in both provinces between 1990 and 2020 with opposing outcomes. I conclude by highlighting aspects of the provinces' historical, social, and discursive contexts that help explain these different outcomes and consider the effects of Alberta's policy to fund private schools with public funds on enrollment and equity.