Hundreds of infuriated parents and staff members descended on Portland Public Schools’ headquarters Tuesday night to protest far-reaching proposals to close up to 14 schools, shift grade configurations and programs and redraw attendance boundaries. In numbers not seen since the Portland Association of Teachers strike, demonstrators chanted and cheered outside the district headquarters and scolded school board members during their meeting inside the building. about half of the district’s elementary schools have fewer than 300 students and a handful have only half that number — it gets harder to afford stable staffing.