1. Reasons Why America Has A Two Party System

2. Strong Consensus on Core Political Values
Americans share a strong commitment to a group of core political values that include belief in
Freedom
Political Equality
Individualism
Equality Under the Law

3. Strong Consensus on Core Political Values
America has never had a strong socialist party dedicated to creating an entirely new political system.
Most Americans identify themselves as moderates who hold beliefs that fall between liberal and conservative views.

4. Single Member Districts
Almost all American elections are held in single-member districts where only one candidate is elected to each office on the ballot.
In single-member district elections, the candidate who receives the most votes is the winner.
It is important to note the difference between a plurality and a majority.
In a Plurality election, the winning candidate is the person who receives the most votes.
In a majority election the winning candidate is the person who receives more than half of all votes cast.

5. Single Member Districts
The winner-take-all, single-member district plurality system is very different than a system based on proportional representation.
In a system based on proportional representation, each party is awarded legislative seats ion proportion to the vote it receives.
For example, in a state with 10 congressional seats, a party receiving 20% of the vote would be awarded 2 seats.
In contrast, in a winner-take-all, single-member district system, the same party would receive no seats.

6. Single Member Districts
An electoral system based on winner-take-all, single-member districts discourages the emergence of minor parties by forcing t hem to wager expensive campaigns with a minimal chance of winning political offices.
The electoral system based on single-member districts produces legislature dominated by two political parties.

7. Test Tip
The AP U.S. Government and Politics exam committee has written several multiple-choice questions designed to test your knowledge of America’s system of winner-take-all, single-member districts.
Be sure you know that this system makes it difficult for new parties to emerge, thus preserving the two-party system.

8. Legal Barriers to Third Parties
The names of Democratic and Republican candidates are automatically placed on state ballots.
In contrast, minor party candidates must persuade registered voters to sign petitions in order to have their manes placed on the ballot.

9. The Force of Historic Tradition
America ha had a two-party system since 1800.
The two-party system has generated self-perpetuating laws and traditions.
As a result, it is very difficult for a minor party to become a major force in American politics.