Over the last decades Latin American countries have increasingly limited access to the representative process to ideal-typical political parties. This raises the question to what extent parties' exclusive claims over the representative process can be legitimized through legal validation. A discussion of instances of cartelizing party laws shows the limits of this strategy, as these attempts all collapsed under demands for political change. A similar backlash is visible in cases where the rejection of parties' representative claims led to their deregulation. The legal validation of political parties is hence not sufficient for the legitimization of the political status quo in terms of party. Instead, this paper shows that elites that build their power merely on the formal rules of the game risk eating away at the political legitimacy of the system that these rules seek to uphold.