Interest groups are associations of individuals or of organizations that form to advance a common political, economic, or social agenda. The political science discipline sees interest groups as crucial to the American political system and as complementary to the political parties. People organize into associations and interest groups for nonpolitical purposes as well, as part of their economic, social, and religious existence. In the political realm, meanwhile, interest groups articulate and advance the political positions and beliefs of citizens, while the political parties attempt to aggregate those positions into coherent party platforms. For instance, during the New Deal Era, the Democratic Party of President Franklin D. Roosevelt aggregated the interests of farmers, industrial unions, big cities, [Page 1151]and the southern states in what was known ...