By Levi Clancy for Student Reader on
Interest groups attempt to affect policy by organizing people with common interests and communicating views to policymakers. Policymakers listen to public and private interest groups because policymakers need:
money for campaign contributions;
manpower for stuffing envelopes, putting up lawn-signs, etc;
information, such as details on parts per million of pollutants in air.
Information plays an especially important role. Interest groups tend to focus all of their energy on a single topic, and are usually very knowledgeable about a specific area of interest.