Most approaches to understanding opposition politics in Yemen take the various groups involved in such politics as preexisting and in some sense “prepolitical”: the Houthis are understood through their religious identity, members of the Southern Movement by their regional identity, and so forth. Analysis of the Joint Meeting Parties opposition alliance, however, offers the opportunity to explore new political identities in the making. Rather than viewing members as attached to the JMP secondary to their primary attachments to existing political parties with distinctive ideologies - from the Islamist Islah to the Leftist YSP or Nasserists – this paper explores the possibility of an emergent common identity among middle-tier leaders of the alliance. Moreover, it traces the mechanisms that have made this identity possible, from organized student politics in the 1990s to shared membership in professional syndicates, to the independent media that has formed a common “staging ground” through which the JMP platform has been articulated. Employing insights from social movement theory, this paper argues that while this emergent identity has offered a more coherent political message, it has come at the cost of political efficacy. As the middle-tier leadership of the JMP has become more committed to the alliance, this has highlighted generational cleavages within the member parties and encouraged the development of other ancillary organizations that work at cross-purposes to the JMP.