Is usually called an issue party.
An example of a minor party focused on solving one problem in American life is the Green Party, which is dedicated to addressing environmental issues. They advocate for policies aimed at combatting climate change and promoting sustainability in all aspects of life.
The minor party that is formed to address one problem is known as a single-issue party.
single issue party
A minor party is one that has very few or no officially elected members. Examples of minor parties include the Green party and the Libertarian party.
The members of a minor party tend to support the platform of a major party.
Reform Party
Third party
the minor party candidate is likely to draw votes from the opposition.
A minor party introduced the idea of national nominating conventions.
Gaining interest in the party's message.
Populist Party
Libertarian Party