Answer:
An interest group is any association that attempts to shape public policy and advance their shared interests for a particula problem or cause. Usually interest groups or special interest groups are formally organized and they pressure politicians to apply policies and make changes that favor their interests.
Step-by-step explanation:
Examples of powerful special interest groups in the United States are the American Civil Liberties Union (ACLU), the National Rifle Association (NRA), National Association for the Advancement of Colored People (NAACP), and UnidosUS. These groups have helped to shape policy and act as watchdogs for their interests vis-a-vis the actions taken by politicians in Washington, DC.