Whatever else they are about, debates over social policy concern what government should do to influence the well-being and life chances of citizens. The question does not afford a single answer. Faced with social problems, political leaders might turn to new or expanded public programs, they might try to encourage or rechannel private-sector activities, or they might choose to do nothing at all. Myriad possibilities, of course, lie between these options, each relying on different governing instruments – from spending to tax breaks to regulation – each defining differently the scope of public and private responsibility. Anyone who has followed recent political struggles over social policy in the United States cannot fail to be impressed by the diversity and complexity of the choices on the table or the ferocity of the battles over them. The bitterness of these disagreements is itself a reminder of their importance. How government will pursue social welfare aims, whether protections are provided by government or the private sector, which tools of public policy are used – resolution of these issues fundamentally shapes the character of a nation's social policies and who benefits and loses under those policies. It is little surprise, then, that they have been at the heart of the struggle over U.S. social policy from the dawn of the modern American state.