This article discusses what political science (does not) know about why provinces within countries have different regimes. Specifically, the article evaluates the literature on subnational regime heterogeneity (SRH). After locating the origins of SRH in the regime change literature, the text discusses our current understanding of SRH and identifies important limitations. To overcome them, the article calls for 1) reviewing national level analyzes with a subnational lens, 2) to articulate a mixed subnational approach that balances structure and agency, and invites 3) weighing the exchange between the level of analysis and the complexity of theorized causal mechanisms. Likewise, using evidence from Argentina, Brazil, and Mexico, the article invites us to 4) unfreeze the story. With this agenda, scholars of subnational politics will be able to (re)ignite the discussion and deepen our knowledge on the subject.