In the Assembly, Isaac serves as Chair of the Committee on Natural Resources as well as Chair of the Assembly's first Select Committee on Poverty and Economic Inclusion. In addition, he serves as a member of the following committees- Appropriations, Government Organization, Judiciary, and Privacy & Consumer Protection. In 2022, he was elected Treasurer of the California Legislative Black Caucus. He is Vice Chair and a founding member of the Renters Caucus.

In the Assembly, Isaac secured funding to establish the Center on Reproductive Health, Law, and Policy at UCLA School of Law; the first Climate Change Education Center in the California Community College system at West LA College; a stipend program for students in the trades to earn a living wage while studying for certificates, and millions of dollars for other projects across the 55th District. Isaac's legislative accomplishments have included phasing out the Inglewood Oil Field and other oil drilling near homes and communities in California (SB-1137), ending prison gerrymandering (AB-1848), ending punishing fees for parents with children in foster care (AB-1686), protecting students from predatory insurance practices (AB-1823) and strengthening online campaign finance disclosure requirement (AB-1848).

Isaac is a community organizer, policy expert, and a published academic. Prior to his election to the Assembly, Isaac led a ballot measure that brought millions of dollars a year to address racial injustice and strengthen communities in Los Angeles. He served as the founding Director of the UCLA Black Policy Project - a think tank dedicated to advancing racial equity through rigorous policy analysis - and as the first Director of Public Policy at the UCLA Ralph J. Bunche Center, as well as Director of Organizing for the nationally recognized Million Dollar Hoods project, a community-based participatory research project. He authored the first holistic report for the City of Los Angeles on the needs of the formerly incarcerated Angelenos, which exposed a gap in youth justice policy. For years, his academic and organizing work has been at the intersection of environmental, economic, education and housing justice.