[Excerpt] Why have labor movements in New York City and Los Angeles changed so dramatically? And more specifically, why have the activist social coalitions that revitalized the labor movement in Los Angeles not played the same kind of role in New York? Our research persuades us that the relationship between .contrasting coalition types—political and social—is central to explaining the differences. Political coalitions refer to cooperation between unions and parties, politicians, and other social actors, focused largely on elections and policy-making processes. Social coalitions, by contrast, include labor and other social actors such as community, religious, environmental, and immigrant rights groups, focused on a range of political, economic, and social campaigns. A comparison of the two metropolitan areas over the past two decades reveals distinct patterns of coalition building in New York and Los Angeles. In New York, the labor movement is dominated by several powerful local unions, often at odds with one another in contending political coalitions. New social coalitions have developed but are not central to organized labor's political action. The focus of most unions on narrow interest representation contributes to a disconnect between social and political coalitions in which the latter dominate. In Los Angeles, by contrast, the significance of social coalition building stands out as the labor movement has coalesced over the past fifteen years. To be sure, labor in Los Angeles participates actively in political coalitions. In contrast to New York, however, political coalitions move beyond narrow union interests, building on social coalitions that broaden the influence of labor as a whole.