This article describes the COMET (Construction Organizing Membership Education Training) program. Faced with declining membership and market share and an erosion of bargaining strength and political influence, building trades unions have undertaken a number of Initiatives to reverse their fortunes. COMET, an educational program that generates membership support and participation in organizing, has emerged as one of the most noteworthy of these new initiatives. Before COMET, organizing efforts were stymied by the reluctance of many union members and leaders to recruit into membership the large nonunion workforce. COMET appears to have transformed the political culture within those local unions that have utilized it by placing organizing on the top of their agendas. Although organizing activity and effectiveness are growing, it may be too soon to tell if construction unions can use COMET to successfully re-unionize the industry.