We trace the origin of party organizations and voters’ political preferences in Argentina and Chile adding background information that is critical for placing our empirical cases in their historical context. Whereas in the short-run, the preferences of voters and the endowments of parties are fixed, in the long run, the historical evolution of electoral competition shapes parties’ non-policy endowments and linkages to voters. In Chile, multiparty competition generated incentives for ideological differentiation sustained by the cleavages generated by democratic transition and the electoral system. Valuable ideological shortcuts facilitated their connection to party organization and competence evaluations in the minds of voters whereas good economic performance and limits to discretionary spending maintained even competence evaluations and distributive expectations. Argentina’s catch-all parties embarked on policy switching after democratization in response to economic volatility, thereby weakening the informational value of ideological shortcuts. Because two major economic crises happened under Radical incumbents, perceptions of economic competence were biased in favor of the Peronists whereas the combination of access to subnational offices and discretionary resources granted them better distributive expectations and capacity to sustain activists’ networks.