Final answer:
Third parties influence politics by emphasizing important issues to the public and acting as spoilers in elections that can change the outcome. They also engage in grassroots movements or represent ignored societal groups, ensuring a variety of political discourses.
Step-by-step explanation:
Third parties can influence politics in several ways, but two common methods stand out. Firstly, third parties often highlight issues that are of significance to mainstream American society. For instance, current third parties like the Libertarian, Reform, Green, and Constitution parties focus on a variety of issues, ranging from individual liberties to environmental concerns. Secondly, third parties can act as spoilers in elections by siphoning votes away from main political parties, potentially altering the outcome. The 2000 Bush v. Gore election serves as an example where Ralph Nader and the Green Party are often cited for influencing the result.
Beyond the elections themselves, third parties also participate in 'grassroots' movements to mobilize public support for certain issues from the ground up. However, some interest groups engage in 'Astroturfing,' which mimics grassroots movements but originates from the interest group rather than the populace. Additionally, third parties may represent ignored groups in society and their issues, contributing to a more diverse political discourse and keeping the major parties accountable and responsive to citizens' needs.