Throughout the Middle East, Islamists, leftists, and other ideological streams are forming coalitions in opposition to their authoritarian regimes. Yet little research has been conducted on the conditions under which these cross-ideological coalitions fail or succeed. Three cases of successful coalition building and one case of failed coalition building in Jordan indicate that cross-ideological coalitions are initiated in the context of external threat and facilitated by organizational forms that ensure the members gain or maintain their ability to pursue their independent goals. Most important, in contrast to other studies, these cases show that the plentifulness of recruits impedes cooperation. Rather than alleviating competition, an abundance of potential recruits increases competition and hinders cross-ideological cooperation.