In this chapter, I advance a novel measure of political polarization along an affective dimension. I argue that polarization carries a significant affective component, crucial for its accurate understanding and assessment. I discuss how existing measures of affective polarization are vague, failing to explicitly or concretely address citizens’ affective experiences, and I show that there is a gap between an academic notion of political polarization characterized by strong emotional fervour and the “soft” and ambiguous measures commonly employed in academic research. Empirically grounded in the notably polarized Mexican society, this study develops a measurement approach that addresses these shortcomings. I introduce a survey item anchored in two specific and opposing (positive/negative) affective states (triggered by polarizing political figures) typical of conflict between polarized groups. The item was tested in two nationally representative field surveys conducted in Mexico in 2021 (n = 1019) and 2022 (n = 1000). Results show high reliability: nearly identical distributions across both years, confirmed by statistical tests for distribution equality; a pronounced bias towards one of the two groups in conflict—a pattern missed by traditional polarization measures but consistent with other political variables, underscoring the item’s potential to capture the “political reality”; and consistently higher response rates than conventional polarization metrics, suggesting the measure taps into a more immediate and accessible dimension for the individual.