What principle does Duverger's Law illustrate regarding electoral systems?

Duverger's Law illustrates the tendency of single-member district electoral systems with plurality voting to favor a two-party system. This principle is grounded in the mechanics of how votes are translated into seats in the legislature. In a plurality system, voters often gravitate towards the candidates from the two leading parties because viable third-party candidates struggle to win elections due to the winner-take-all aspect of this system.

As such, voters may choose not to "waste" their votes on a candidate who has little chance of winning, which reinforces the dominance of the two major parties over time. This phenomenon creates a political landscape where two main parties become entrenched, leading to a reduction in the influence of smaller parties. Consequently, the dynamics of this electoral structure lead not only to the consolidation of political power but also to a lack of diversity in political representation, as the two main parties often adopt similar platforms to attract a wider voter base.

In contrast, systems that encourage multiple parties tend to employ proportional representation or ranked-choice voting, which are not aligned with the mechanics of single-member districts and plurality voting that Duverger's Law describes. Thus, this law helps to explain why specific electoral frameworks result in a two-party system and reveals important implications for political