Since the 1990s, charter schools have spread rapidly across the nation. The replication and expansion of charter schools has become a common feature of the portfolio management model which situates the district as strategic manager of a choice-based system including traditional and charter schools. Yet, many school districts have experienced substantial political, logistical, and technical challenges in managing and "right-sizing" the charter sectors in their communities. The Los Angeles Unified School District presents a strategic case to examine the challenges of charter expansion in a portfolio management model district. Using a micropolitical lens, we examine how political tensions over charter schools in Los Angeles affected one expanding charter network in LAUSD. This 3-year case study draws on interviews and focus groups with 48 charter leaders, teachers, and parents. We find that broader political tensions over charter schools in Los Angeles affected the network in material ways that challenge important assumptions of the functioning of LAUSD's portfolio model. Specifically, we find that political tensions between the network and the district challenge a central assumption of the portfolio approach: namely, that the portfolio district can effectively operate as a neutral manager optimizing performance across schools in the portfolio. These political tensions also affected how this charter network managed instructional practice and parent engagement. This analysis offers important dimensionality to our understanding of organizational responses in portfolio district settings.