These are political parties in the United States other than the two major parties (Democratic and Republican). They often focus on specific issues that may not be addressed by the major parties.
Related terms
Libertarian Party: A third party in US politics that emphasizes individual liberty, non-interventionism, laissez-faire capitalism, and shrinking the size and scope of government.
Green Party: Another third party in US politics that focuses on green politics, including environmentalism, non-violence, social justice and grassroots democracy.
Populist Party: A historical third party in US politics from late 19th century which advocated for various reforms like a graduated income tax and an eight-hour work day.