This document discusses political parties and their role in American politics. It defines political parties as coalitions that recruit, nominate, and elect candidates to control the government according to their ideas and policies. Political parties serve as intermediaries between citizens and the government, nominate candidates, contest elections to mobilize voters, organize the government, provide accountability, manage conflicts between groups, and present ideological positions to voters. The document also discusses examples of third parties throughout history and barriers that make it difficult for third parties to emerge.