Final answer:
A two-party system is characterized by the dominance of two major political parties which often share basic political values. In such a system, minor parties exist but due to electoral rules and voting procedures, they struggle to gain significance. The U.S. has a two-party system shaped by its history, electoral system, and the broad consensus on key principles.
Step-by-step explanation:
A two-party system in politics is characterized by the dominance of two major political parties within a political landscape. This system facilitates a broad consensus on fundamental political values within a country, where both major parties typically agree on key principles such as liberty, equality, and individualism. Unlike multiparty systems where beliefs might vary more widely and disagreements can be deeper, a two-party system tends to have less ideological diversity. In the United States, for example, the two dominant parties are the Democrats and Republicans. While third parties such as the Green Party, Libertarian Party, and others do exist, they face significant challenges in gaining traction due to the winner-take-all electoral system and voting procedures like plurality voting.
Historically in the U.S., electoral rules and the winner-take-all Electoral College system have promoted the existence of a two-party system. Even though minor parties occasionally influence political discourse and election outcomes, they have yet to gain the widespread support necessary to challenge the two-party system successfully. The U.S. political system, while stable in its two-party nature, periodically experiences shifts in party coalitions and ideologies, reflecting changes in the electorate's preferences and the country's sociopolitical landscape.