The Constitution never mentions political parties, and George Washington's Farewell Address (1796) warned against "the spirit of party." Yet within a few years Americans had formed the first parties, Federalists and Democratic-Republicans, and parties have organized politics ever since. Like the interest groups you studied, they link citizens to government, but parties run candidates under their own name.
| What parties do | Example |
|---|---|
| Recruit and nominate candidates | primaries and conventions choose each party's nominee |
| Organize voters and campaigns | register voters, raise money, turn out supporters |
| Give voters a shortcut | a party label signals a candidate's general views |
| Organize the government | the majority party in each house picks its leaders and committee chairs |
| Serve as the loyal opposition | the party out of power criticizes and offers alternatives |
Why it works
Why only two big parties? Most American elections use single-member districts with winner-take-all (plurality) rules: one seat, and whoever gets the most votes wins it. A third party that wins 20 percent everywhere may win no seats at all, so voters and politicians drift toward the two parties that can win. Political scientists call this tendency Duverger's law. Systems with proportional representation, common in Europe, tend to have more parties. Ballot-access rules and the Electoral College add to the effect. Third parties still matter: they raise issues the big parties later adopt. Theodore Roosevelt's Progressive ("Bull Moose") Party won 88 electoral votes in 1912, the best third-party showing, and Ross Perot won about 19 percent of the popular vote in 1992 but no electoral votes.
Key idea
Parties recruit candidates, organize voters and run the government. The U.S. has a two-party system, encouraged by single-member districts with winner-take-all rules; third parties raise issues but rarely win. Parties are not in the Constitution.
Worked example: Seats from votes
In a state with 10 single-member districts, Party C wins 20 percent of the vote in every district, but in each one another party wins more. How many seats does Party C win?
- Each district elects one member, the top vote-getter.
- Party C is never first.
Answer: Zero seats, despite 20 percent of the vote.
Worked example: Under proportional representation
If those 10 seats were divided in proportion to the statewide vote, how many would Party C get?
- 20 percent of 10 seats is 2.
Answer: Two seats.
Common mistake
Thinking the Constitution creates the two parties. Parties are not in the Constitution; the election rules make two large parties likely. Check: where does the rule come from: the Constitution, a state law, or the parties themselves?