As @jasode said in another comment [0]: > In terms of cause & effect, the USA's 2-party system is the effect caused by the voting system: https://en.wikipedia.

As @jasode said in another comment [0]: > In terms of cause & effect, the USA's 2-party system is the effect caused by the voting system: https://en.wikipedia.org/wiki/Duverger%27s_law https://en.wikipedia.org/wiki/Duverger%27s_law [0]: https://news.ycombinator.com/item?id=31503357 https://news.ycombinator.com/item?id=31503357