What Are Interest Groups? Definition and Examples

Demonstrators from the Sierra Club, Workers For Progress, Our Revolution, and the Chesapeake Climate Action Network picket in front of the office of US Senator Shelley Moore Capito.
Demonstrators from the Sierra Club, Workers For Progress, Our Revolution, and the Chesapeake Climate Action Network picket in front of the office of US Senator Shelley Moore Capito.

Jeff Swensen / Getty Images

Interest groups are groups of people, whether loosely or formally organized, that work to encourage or prevent changes in public policy without trying to be elected themselves. Sometimes also called “special interest groups” or “advocacy groups,” interest groups typically work to affect public policy in ways that benefit themselves or their causes.

What Interest Groups Do

As anticipated by the framers of the U.S. Constitution, interest groups serve an essential function in American democracy by representing the needs and opinions of individuals, corporate interests, and the general public before the government. In doing so, interest groups approach all three branches of government at the federal, state, and local levels to inform lawmakers and the public about issues and monitor the actions of the government while promoting policies that benefit their causes.

Immigration activists with the advocacy group CASA rally at the White House to demand President Biden grant citizenship for immigrants.
Immigration activists with the advocacy group CASA rally at the White House to demand President Biden grant citizenship for immigrants. Kevin Dietsch / Getty Images

As the most common type of interest group, political interest groups typically engage in lobbying to achieve their objectives. Lobbying involves sending paid representatives called lobbyists to Washington, D.C., or state capitals to encourage members of Congress or state legislators to introduce or vote for legislation that benefits the member of the group. For example, many interest groups continue to speak out for and against various aspects of universal government health insurance. Enacted in 2010, the Affordable Care Act, also known as Obamacare, was a major overhaul of the U.S. healthcare system. In reaction to its sweeping impact, interest group lobbyists representing the insurance industry, health care providers, medical product and pharmaceutical manufacturers, patients, and employers all worked to influence how the law would operate.

Along with paid lobbyists, interest groups often organize “grassroots” movements—organized efforts, undertaken by ordinary groups of citizens in a given geographic—area to bring about changes in social policy or influence an outcome, often of a political issue. Now nationwide movements such as Mothers Against Drunk Driving (MADD) and the #Me Too effort to combat sexual abuse and harassment grew out of local grassroots campaigns.

Outside of working directly to influence government policymakers, interest groups often conduct beneficial outreach programs within the community. For example, while the Sierra Club focuses primarily on promoting policy protecting the environment, the group also conducts educational outreach programs to help ordinary people experience nature and to become involved in conservation and the protection of wilderness and biological diversity.

One criticism of interest groups is that they serve only to increase the income of their membership without any added value or service. However, many interest groups also perform vital community services. For example, the professional interest group, the American Medical Association (AMA), conducts significant amounts of member and public education work and carries out a substantial amount of charity work. 

Types of Interest Groups

Today, so many organized lobbying groups represent so many issues and segments of society that the line between “special” interests and those of the American people as a whole has become blurred. In a sense, the American people are the largest, most influential interest group of all.

A majority of the 23,000 entries in the Encyclopedia of Associations qualify as interest groups. Most of these are based in Washington, D.C., allowing them easy access to legislators and policymakers. Interest groups can be grouped into a few broad overarching categories. 

Economic Interest Groups

Economic interest groups include organizations that lobby for big business. For example, the U.S. Chamber of Commerce and the National Association of Manufacturers represent companies of all sizes across every sector of the economy. Powerful labor lobbies like the AFL-CIO and the International Brotherhood of Teamsters represent their union members in virtually every occupation imaginable. Trade associations represent specific industries. For example, the American Farm Bureau represents the American agriculture industry, from small family farms to large corporate farms.

Public Interest Groups

Public interest groups promote issues of general public concern such as environmental protection, human rights, and consumer rights. While these groups do not expect to profit directly from the policy changes they promote, the activists who staff them profit from donations from individuals and foundations who support their activities. While most public interest groups function in a politically nonpartisan manner, some of them engage in clearly political activities. For example, when Republican Senator Mitch McConnell successfully filibustered a Democratic measure to investigate the January 6, 2021 attack on the Capitol Building, the group Common Cause–which advocates for more effective government—sought donations to “stop the far-right’s anti-democracy power grabs.”

Civil Rights Interest Groups

Today, civil rights interest groups represent groups of people that have historically have faced discrimination and, in many cases, continue to be denied equal opportunity in areas such as employment, housing, education, and other individual rights. Beyond racial discrimination, groups such as the National Association for the Advancement of Colored People (NAACP), the National Organization for Women (NOW), the League of United Latin American Citizens (LULAC), and the National LGBTQ Task Force address a wide variety of issues including welfare reform, immigration policy, affirmative action, gender-based discrimination, and equal access to the political system.

Ideological Interest Groups

Based on their political ideology, usually liberal or conservative, ideological interest groups address issues such as government spending, taxes, foreign policy, and federal court appointments. They support or oppose legislation or policy depending entirely on whether they find it ideologically sound.

Religious Interest Groups

Despite the doctrine of separation of church and state inferred by the “Establishment Clause” of the First Amendment, most religious groups occupy an important position within the American political process by serving as a form of “intermediary” agents existing between the elected officials and the mass public. For example, the Christian Coalition of America, which draws support from conservative Protestant groups, lobbies in support of school prayer, opposition to LGBTQ rights, and passage of a constitutional amendment banning abortion. Since the early 1990s, it has played an increasingly important role in politics, particularly in the Republican Party. Founded in 1992, the socially conservative Government is Not God Political Action Committee has raised funds to support candidates who believe that “God is God and the Government should never try to be.” It has been estimated that religious interest groups collectively spend over $350 million every year attempting to incorporate their religious values into the law.

Single-Issue Interest Groups

Mothers Against Drunk Driving (MADD) National President Millie Webb speaks during a 20th anniversary rally outside the U.S. Capitol, September 6, 2000 in Washington.
Mothers Against Drunk Driving (MADD) National President Millie Webb speaks during a 20th anniversary rally outside the U.S. Capitol, September 6, 2000 in Washington. Michael Smith / Getty Images

These groups lobby for or against a single issue. While many interest groups take a stance for or against gun control as a part of a wider political agenda, it is the only issue for the anti-gun control National Rifle Association (NRA) and the pro-gun control National Coalition to Ban Handguns (NCBH). Similarly, the abortion rights debate pits the pro-life National Right to Life Committee (NRLC) against the pro-choice National Abortion Rights Action League (NARAL). By the nature of their issues, some single-issue interest groups do not generate organized opposition. For example Mothers Against Drunk Driving (MADD), which campaigns for stiffer sentences for driving while intoxicated or drugged and mandatory penalties for the first offenses, clearly has no “pro-drunk driving” counterpart.


Interest groups typically use both direct and indirect strategies when attempting to persuade lawmakers to pass legislation and support policy that benefits their membership.

Direct Techniques

Some of the more specific direct strategies used by interest groups include:

Lobbying: Professionals lobbyists, working for consulting firms or the interest groups themselves, may meet privately with government officials, testify at legislative hearings, consult in drafting legislation, and offer political “advice” to legislators on proposed bills. 

Rating Elected Officials: Many interest groups assign legislators scores based on the percentage of times they voted for or against the group’s position. By publicizing these scores, interest groups hope to influence the future behavior of the legislators. For example, the environmental group League of Conservation Voters publishes an annual “Dirty Dozen” list of incumbent candidates—regardless of party affiliation—who consistently voted against environmental protection measures. Groups such as the liberal Americans for Democratic Action (ADA) and the conservative American Conservative Union (ACU) rate the voting records of incumbent elected officials according to their corresponding ideologies. A Democratic challenger, for example, might emphasize an incumbent opponent’s high ACU rating as an indication that he or she is too conservative to represent the people of the traditionally liberal-leaning district. 

Alliance Building: Since in politics, there is true “strength in numbers,” interest groups try to form coalitions with other groups concerned about similar issues or legislation. Combining their efforts allows the groups to multiply the influence of the individual groups, as well as share the costs of lobbying. Most importantly, the alliance of several groups imparts the impression to lawmakers that a much larger public interest is at stake.

Offering Campaign Assistance: Perhaps most controversially, interest groups often offer assistance to candidates in hopes of gaining their legislative support. This assistance may include money, volunteer campaign workers, or the group’s public endorsement for the candidate’s election. The endorsement from a big interest group, such as the American Association of Retired People (AARP) or a major labor union goes a long way in helping a candidate win or retain their office.

Indirect Techniques

Interest groups also work to influence government policy by working through others, typically members of the general public. Stimulating widespread public support helps interest groups mask their activities, making their efforts appear to be spontaneous “grassroots” movements. Such indirect efforts may include mass mailings, political ads, and postings on social media internet websites.

Pros and Cons

While the Constitution makes no mention of interest groups, the Framers were acutely aware that individuals, as many of them had to oppose oppressive British laws, band together in an attempt to influence the government. James Madison, in Federalist No. 10, warned of “factions,” minorities who would organize around issues they felt strongly about, possibly to the detriment of the majority. However, Madison opposed measures to limit such factions, as doing so would violate individual freedoms. Instead, Madison believed that the way to keep individual interest groups from becoming too powerful was to allow them to flourish and compete with each other.


Today, interest groups perform several functions that are beneficial to American democracy:

  • They generate greater awareness of public affairs and the actions of the government.
  • They provide specialized information to government officials.
  • They represent issues to lawmakers based on the shared attitudes of their members rather than shared geography.
  • They stimulate political participation.
  • They provide additional checks and balances by competing with one another in the political arena.


On the other hand, interest groups can pose problems:

  • Depending on how much money they have to spend on lobbying, some groups can impose influence far out of proportion to the size of their membership.
  • It is often hard to determine how many people an interest group represents.
  • Some groups gain influence through unfair or illegal lobbying practices, such as corruption, bribery, and fraud. 
  • They can lead to “hyperpluralism”—a political system that caters only to interest groups and not the people.
  • Interest groups may lobby for ideas that are not in the best interest of society.

Based on these pros and cons, interest groups can provide many benefits, but they can also come with drawbacks that cause them to experience serious issues. Despite these drawbacks, however, the fact remains that there is power in numbers, and elected officials are more likely to respond to a collective rather than to an individual voice. James Madison’s “factions” are not exactly today’s interest groups. By competing with each other in representing diverse segments of the people, interest groups continue to offset one of Madison’s main fears—the domination of the majority by the minority.  


  • “Functions and Types of Interest Groups in the United States.” Course Hero, (video), https://www.youtube.com/watch?v=BvXBtvO8Fho.
  • “Encyclopedia of Associations: National Organizations.” Gale, 55th Edition, March 2016, ISBN-10: 1414487851.
  • “Interest Groups Campaign Contributions Database.” OpenSecrets.org, https://www.opensecrets.org/industries/.
  • “Leading lobbying industries in the United States in 2020, by total lobbying spending.” Statista, https://www.statista.com/statistics/257364/top-lobbying-industries-in-the-us/.
  • Sharif, Zara. “Do More Powerful Interest Groups Have a Disproportionate Influence on Policy?” De Economist, 2019, https://link.springer.com/article/10.1007/s10645-019-09338-w.
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Longley, Robert. "What Are Interest Groups? Definition and Examples." ThoughtCo, Jul. 29, 2021, thoughtco.com/interest-groups-definition-and-examples-5194792. Longley, Robert. (2021, July 29). What Are Interest Groups? Definition and Examples. Retrieved from https://www.thoughtco.com/interest-groups-definition-and-examples-5194792 Longley, Robert. "What Are Interest Groups? Definition and Examples." ThoughtCo. https://www.thoughtco.com/interest-groups-definition-and-examples-5194792 (accessed March 26, 2023).