This article will detail efforts to broaden participation in computing in urban schools through a comprehensive reform effort of curricular development, teacher professional development, and policy changes. Beginning with an account of the curricular development of "Exploring Computer Science", we will describe the inquiry-based research that underlies these learning materials. Next, we argue that accompanying professional development that supports the curriculum is essential for supporting this inquiry-based approach to computer science instruction. We then explain the policy strategies used to designate this course as a college-preparatory elective and place it in 17 Los Angeles high schools. Finally, we share the initial results of how students experience this course and ongoing challenges encountered when working in the public school system. The article concludes with a discussion of how longitudinal reform effort requires a strong foundation and deep roots to successfully democratize computer science education. (Contains 1 table.)