Answer: A two-party system has developed
Notes: The United States and the United Kingdom use two-party systems. These systems limit viable electoral parties to two, often due to plurality voting. In such systems, proportional representation has less impact because most legislative seats are divided between the two main parties. The Second Ballot Act 1906 in the UK led toward two-party dominance. Two-party systems emerged in the United States by the 19th century.
