Between Party and Movement: Democratic Socialists of America and Momentum

Social movements and political parties play pivotal roles in shaping political landscapes. Within established center-left parties, organizations often emerge that blur the lines between internal factions and independent movements. This article examines two prominent contemporary examples: the Democratic Socialists of America (DSA) within the context of the US Democratic Party, and Momentum within the UK Labour Party. While such formations have historical precedents, DSA and Momentum exhibit distinct characteristics shaped by recent political shifts, digital mobilization, and their navigation of the space between formalized party structures and grassroots activism. This article aims to characterize the roles, structures, and strategies of these two organizations and analyze the implications they hold for left-wing politics within two Anglo-Saxon countries (USA and UK) where the concept of socialism has historically been marginalized. Adopting a qualitative comparative methodology drawing on organizational documents, secondary academic literature, and media analysis, the research explores how these groups attempt to influence their respective parties while maintaining grassroots energy. The comparative analysis suggests that while facing significant challenges, these hybrid organizations represent a key dynamic in contemporary Western left-wing politics, reflecting tensions between institutional engagement and movement-based mobilization in an era where traditional party models are under pressure.