While dislike of opposing parties, that is, affective polarization, is a defining feature of contemporary politics, research on this topic largely centers on the United States. We introduce an approach that analyzes affective polarization between pairs of parties, bridging the US two-party system and multiparty systems in other democracies. Analyzing survey data from twenty Western democracies since the mid-1990s, first, we show that partisans' dislike of out-parties is linked to elite policy disagreements on economic issues and, increasingly over time, also to cultural issues. Secondly, we argue and empirically demonstrate that governing coalition partners in parliamentary democracies display much warmer feelings toward each other than we would expect based on elite policy (dis)agreements. Third, we show that radical right parties are disliked much more intensely than we would expect based on policy disputes and coalition arrangements. These findings highlight the policy-based and institutional underpinnings of affective polarization.