This paper reconsiders long-standing debates in Canada about the relationship between language, race, and culture. Federal policies focused on official bilingualism (1969) and multiculturalism (1971) animated local movements of parents, students, and other community members demanding greater linguistic and racial inclusion in schools. This paper examines two instances of these grassroots politics, namely activism on behalf of heritage-language education and Black cultural-heritage programs, in Toronto, Ontario, between 1970 and 1987. Our analysis reveals key instances in which temporary forms of solidarity emerged between heritage-language and Black activism, as well as contradictory trajectories in this activism that undermined what Roseann Liu and Savannah Shange have theorized as "thick solidarity." In this paper, we argue that absences of thick solidarity ultimately weakened efforts by heritage-language and Black activists alike to reorganize schools in ways that were more linguistically and racially just.