During Argentina’s 2001–02 crisis, new political groupings were created. Most of them were derived from preexisting parties and most failed to survive much beyond that juncture. The Republican Proposal (PRO) is one of the rare cases of successful party building. From a small group centered around an entrepreneur, it was built up with political newcomers from the business world and NGOs and with long-standing politicians – radicals, Peronists – from the traditional Right. Its success marked a break with the historical weakness of center-right parties in Argentina. However, due to the conditions of its emergence and the strategy carried out by its leaders, PRO is more rooted in some parts of the country than in others. In the City of Buenos Aires, its stronghold, and in certain other provinces, it behaves like a fully functioning political party, while in other districts it would be better defined as a diminished subtype, specifically an unrooted party. This chapter focuses on the PRO’s centralized horizontal coordination strategy and the impact of this strategy on the party’s uneven rootedness throughout the country. In this way, the case of the PRO helps elucidate the subnational variations of the theoretical model proposed in this volume.