How can electoral competition remain stable despite a weak party system? We argue that ideological identification can stabilize electoral behavior, serving as a substitute for weak or delegitimized political parties. Focusing on Chile, we combine repeated cross-sectional surveys, a conjoint experiment, and text analysis. We find that while partisanship has declined sharply over the past three decades, ideological self-placement remains remarkably stable. Conjoint results show that ideological alignment outweighs issue alignment in shaping vote choice. Drawing on survey questions and topic modeling of open-ended responses, we uncover emotionally charged and moralized language tied to ideological groups, suggesting that ideology in Chile displays features of a social identity, including intergenerational transmission, symbolic boundaries, and in-group affect. We also examine how intense political events, such as a plebiscite to end a dictatorship, shape long-term ideological attachments. Our findings offer insight into how electoral competition can remain ideologically structured even in the absence of strong parties, a pattern increasingly relevant in contemporary democracies.