The document discusses the two-party system of American politics. It provides historical context for how the two-party system emerged and has been maintained over time through features of the electoral system like single-member districts and winner-take-all rules. While the two parties find ways to agree, the system discourages third parties and maintains an ideological consensus at the moderate center, though there have been times of deep division in the US. The document also contrasts the two-party system with multiparty systems in other countries.