Final answer:
The winner-take-all plurality voting system in the United States, where the candidate with the most votes wins, has helped maintain a two-party system by discouraging third-party success and fostering strategic voting among citizens. Historical political divisions and a focus on individual major party candidates also contribute to the two-party dominance.
Step-by-step explanation:
Electoral Rules and the Two-Party System in the United States
Electoral rules such as the winner-take-all plurality system have played a significant role in maintaining a two-party system in the United States. This system, wherein the candidate with the most votes in an election wins regardless of whether they achieve an absolute majority, inherently discourages the success of third parties. Because voters do not wish to 'waste' their votes on a candidate who is unlikely to win, they often choose between the two major parties, Democrats and Republicans, contributing to their sustained dominance.
The plurality voting system means that even when third parties receive a substantial portion of the vote, they are unlikely to win any representation unless they can secure the most votes in a particular election. This dynamic has led to strategic voting, where citizens vote for a 'lesser-of-two-evils' rather than their preferred choice if that choice is not a part of the two major parties. This strategic voting perpetuates the cycle of a two-party system by creating a barrier to entry for new parties, making it challenging to form a base of voters or raise funds for campaigns.
Furthermore, the historical context of the U.S. has shaped the two-party system, with early political divisions giving rise to the Federalists and Jeffersonian Republicans, and later parties evolving from these original groups. American electoral districts also foster a personal connection between voters and 'their' representative, who is elected through the winner-take-all system, thus enhancing the election's focus on individual candidates from the major parties over a more multiparty approach.