In Latin America leftist political parties that formed under authoritarianism became key participants in the construction of new democratic rules and institutions. An emerging competitive scenario led some of these parties to change their strategy in order to win elections. By comparing Mexico''s Party of the Democratic Revolution (PRD), Brazil''s Workers Party (PT) and Uruguay''s Frente Amplio (FA) this paper seeks to explain variance in the responses of these parties to the opportunities and constraints offered by democratic competition. Drawing from the literature on party transformation, this paper tests the relevance of historical legacies, leadership autonomy, membership entrenchment and the strategic adaptation of main competitors as explanatory variables accounting for these parties’ strategic adaptation paths. It concludes that the propositions put forward by existing literature fit well to explain the strategic adaptation of these parties and that leadership autonomy in particular may be the single most important factor in explaining variance.
