This paper examines how electoral losers respond to election outcomes, a cornerstone of democratic theory in which regime legitimacy depends on the consent of the losers. Empirically, we focus on Spain, a highly polarized democracy that experienced protests during the 2023 government formation process. We analyse the factors that erode citizens’ willingness to accept electoral defeat, with particular attention to political polarization and its attitudinal consequences. The paper also explores whether electoral loss contributes to the emergence of illiberal attitudes among voters. Using individual-level panel data collected over more than a year, we show that the parliamentary agreement forged by Prime Minister Pedro Sánchez to secure his investiture led voters of opposition parties to significantly reduce their willingness to accept being governed by the resulting government. We further find that right-wing voters became more accepting of candidates willing to limit political pluralism, although this shift did not translate into greater support for openly authoritarian leaders. These findings show how polarized contexts can weaken democratic consent and create openings for illiberal attitudes, with important implications for democratic stability in consolidated democracies.