As a legislative aide to S.F. Board President Aaron Peskin, Sarah Souza is a member of International Federation of Professional and Technical Engineers Local 21. She also is vice president of the San Francisco chapter of the Labor Council for Latin American Advancement AFL-CIO. She has been involved in immigrant rights struggles on a national, state and local level. She is an active member of the National League of United Latin American Citizens. She is an executive member of the Chicano Latino Caucus of the California Democratic Party. As a result of her advocacy and joint efforts with statewide leaders, the Governor signed the expansion of Earned Income Tax Credit to immigrant workers. In 2019, she was appointed as the first Dreamer to serve on the DCCC. As co-chair of SF Commissions for All, she led the campaign to pass a charter amendment to allow all San Franciscans, regardless of immigration status, to serve on local boards and commissions.