The film's focus on the 1968 Tlatelolco Massacre inherently critiques state authoritarianism and champions the cause of student movements seeking democratic freedoms, aligning its central thesis with a clearly left-leaning perspective.

The casting for 'Mariana, 1968' appears consistent with its likely Mexican origin, showing no explicit DEI-driven choices based on the available cast information. However, without any plot details or thematic summaries, it is not possible to evaluate the narrative's framing of traditional identities or the presence of DEI themes.