Studies of transnationalism typically account for homeland-oriented transnational political action (TPA) as the product of varying political opportunities. Yet, the opportunity-driven perspective overlooks why some immigrant and diaspora communities refrain from engaging in homeland politics or are forestalled in their attempts to do so. We address this shortcoming by theorizing how sociopolitical conditions can constrain TPA. Drawing inductively from primary data on Pakistani, Syrian, Libyan, and Yemeni diasporas as well as secondary sources, we identify four sources of constraint: 1) geopolitics and interstate relations; 2) origin-country authoritarianism; 3) weak origin-country governance; and 4) exclusionary receiving-country contexts. By demonstrating how these socio-political forces suppress TPA, we contribute a new theoretical approach that emphasizes the conditions and relations that hinder cross-border political action. In sum, the article illustrates the theoretical importance of understanding variation in TPA and the utility of examining negative cases in the study of immigrant and diaspora transnational politics.