Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I even say who wrote them. If you have more recent summaries to add to this collection, send them my way I guess. Sorry for the ads; they cover the costs of keeping this online.
Truman. 1951. The governmental process.
The governmental process can be understood if the role played by interest groups is fully recognized. The essence of politics is the controversy and conflict derived from the interest groups' activities. The competition among them will help the policy-making process. The government plays an active role in establishing the conditions for interest groups to act. Groups who are threatened will take action.
Man is a social animal. Groups will be formed if they interact frequently based in their similar characteristics. Interest groups are those that based on shared attitudes make certain claims, upon other groups in the society for the establishment, maintenance or enhancement of forms of behavior related to those interests. When these claims are done through or upon any of the institutions of the government, it becomes a political interest group.
Against: Schattschenider (1960) parties are the main vehicles for people to express their interests. Olson (1965) about the spontaneity of collective action of smaller groups to succeed relative to larger groups. Lowi (1979) about the lack of real representation of interest groups, since policy-making is sold to the highest bidder group.
Interest groups can become politicized and therefore part of the government institutions. The interest groups' strategic position in the society (groups' status and prestige; their standing against the rules of the game; government membership in these groups; their usefulness as a source of information) and internal characteristics of both the interest groups (degree of organization; the skills of the leadership; and resources/money) and governmental institutions (operating structure; groups' effects on particular branches of the government) affect the influence on governmental decisions. The political structure of the U.S. government (federalism, liberty, rights) allows potential interest groups to rise and therefore play a role in representing interests. Diversity and will accommodate policy-making and will make it more flexible.
Pluralism due to interest groups representation is the 'balance wheel' in the U.S. political system.
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