This article investigates the crisis of representativeness in political decision-making spaces from the perspective of youth collective actions, with a focus on the historical exclusion of marginalized groups such as peripheral youth, Black women, and LGBTQIA+ people. Using an interdisciplinary approach and a qualitative methodology grounded in militant research—including snowball sampling, participant observation, document analysis, and field diary—the study examines whether new social movements have redefined representative practices. The findings indicate that youth collectives act as agents of transformation by challenging institutional structures, expanding the possibilities of democratic participation, and disputing new meanings for contemporary politics.