The study investigates the mechanisms underlying the flag-priming effect on ideological positioning and voting behavior. The experiment, conducted in the context of the Italian elections, found that subliminal flag priming led to self-stereotyping, with participants assuming traits associated with the stereotype of the typical Italian citizen. Such self-stereotyping processes, in turn, mediated the effect of the priming on voting and ideological positioning. Specifically, the priming was responsible for a move toward ideological positions closer to the national prototype (which is centrist), both in terms of voting behavior and ideological positioning. Moreover, the effect proved to be moderated by the centrality of political identity for the individual. This finding helps elucidate previous results and holds practical implications for political communication.