School districts have two general courses of action to maintain fiscal solvency and raise student achievement in the face of drastic funding cuts. They can reduce spending on teachers, a strategy opposed by many teachers' unions because it threatens teacher job security. They can also cut expenditures in other areas such as instructional programs and materials, transportation, or non-teaching personnel, but they risk losing support from parents and community members who want to maintain high-quality options for students. There is a growing body of research showing that boards, superintendents, and teachers' unions (alone and as they interact with one another) are highly influential in the decisions school districts make when they allocate resources. However, there is currently no clear understanding of what in practice defines a "powerful" school board, superintendent, or teachers' union, nor is it widely understood how each uses political power to influence district decision-making. Using a theory-driven comparative instrumental case study of two large, urban, politically-active school districts, I examined how school boards and their members, superintendents and central office administrators, and teachers' union leaders strategically used power to affect the outcomes of decision-making and protect their interests. To frame and analyze case study data, I combined political systems, organizational, and power theories, and then used the resulting framework to describe the power resources available to each group and the strategies each used to leverage their resources. I also investigated contextual determinants of resource availability, strategy choice, and strategy success. This dissertation presents four major findings about the two case study districts. First, the more vocal, visible union that used high-conflict interest group strategies was likely desperate, not powerful. That union was forced to act outside of the district's formal decision-making processes. As a result it had fewer resources, and its power strategies were less successful, than the union that had been invited to act from within. Second, while board members were theoretically the strongest district actors because of their legitimate authority over local education governance, in both case study districts the board was not, in practice, powerful in comparison to other actors. In one district, the board was weaker than the superintendent because it ceded its authority to administrators. In the other, the board diminished their own autonomy when board members were overly responsive to community and union demands. This is related to the third finding: The relative power of the superintendent was contingent on the amount of authority ceded to him by the board and permitted to him by the public. Both superintendents were very powerful when they had the ability to, and chose to, use their sizable knowledge resources and access to decision-making. Finally, certain environmental conditions significantly decreased resource value and strategy effectiveness in these districts. I define these conditions as community constraint (devaluation of existing resources), systemic exclusion (limited access to the resource exchange marketplace), external uncertainty (depletion or elimination of local resources by outside forces), and internal conflict (when resources are frozen by disagreement before they can be used). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]