When Manikka Bowman, candidate for Cambridge School Committee, thinks about the Cambridge Public School System, she thinks about potential - the potential brimming out of each and every student, and the potential of the school system itself. And she thinks about how to turn that potential into reality. Bowman, an ordained clergywoman, knew from an early age that she would someday run for public office. Growing up in the Black church tradition, she looked up to her own pastor