This article reports on a qualitative cross-case study that compares patterns of implementation across community-based public health initiatives resulting in a construct for building the capacity of such initiatives in racial and ethnic communities. By specifying which capacities provide optimum leverage, community initiatives may increase precision in developing intervention strategies that focus on those pivotal capacities that are necessary for producing desired outcomes. First, community capacity is defined and briefly contrasted with social capital. Then the research method is described from which the capacity construct is derived. The study reveals several capacities of community-based initiatives that are crucial in distinguishing highly successful initiatives from those that had greater difficulty in realizing their goals. Leadership was the most important capacity that distinguished highly and less successful initiatives. Organizing capacity, or the propensity to provide structure, operational procedures, oversight, and activity formation were also critical in leveraging community action and desired outcomes. The study concludes that developing high levels of community capacity where it can produce the most strategic advantage is a promising pathway for mitigating antagonistic social factors.