Why Europe Has So Many Parties (And America Has Two)

The Netherlands' most recent national election sent 15 parties to parliament. Germany's sent seven. In the United States, every one of the 435 seats in the House of Representatives went to a Democrat or a Republican in 2024. The difference is often attributed to political culture, as if Europeans were more divided or Americans held a narrower range of views. The more accurate explanation is institutional. The number of parties a country sustains depends largely on one rule: what happens to the votes that do not win.

Winner Takes the District

The United States elects its House through single-member districts under a plurality rule, commonly called first past the post. Each of the 435 districts elects one representative, and the candidate with the most votes wins, even without a majority. A party that finishes second, whether by one vote or by twenty points, receives nothing.

The arrangement has a statutory history. In the early republic, many states elected their entire House delegations at large, allowing the party that carried the state to take every seat. In 1842, Congress required single-member districts. The requirement lapsed and returned over the following century, and Congress restored it in 1967; it remains federal law.

The French political scientist Maurice Duverger described the consequence in the 1950s. Plurality rules squeeze a party system toward two dominant parties through two mechanisms. The first is arithmetic: a third party that finishes second or third across many districts wins few seats. The second is psychological: voters who expect a third party to lose abandon it for the more acceptable of the two major contenders.

The two-party system itself appears nowhere in the Constitution, which does not mention political parties, and no law limits the number of parties that may compete. George Washington's Farewell Address warned against parties altogether. The constraint is the district, not a prohibition.

Europe's Turn to Proportionality

Much of continental Europe took a different path at the turn of the twentieth century, as the franchise expanded to more working men and socialist parties grew rapidly. Established parties recognized that winner-take-all rules could eliminate them. In 1899, Belgium became the first country to allocate national parliamentary seats by vote share. The Catholic Party that enacted the change was dominant at the time and lost 26 seats at the following election, a cost it accepted in exchange for protection against being wiped out.

Proportional representation spread after the First World War. Under it, parties receive shares of parliament that roughly match their shares of the vote. The Netherlands, which adopted the system in 1917, treats the entire country as a single district; a party needs roughly two-thirds of one percent of the national vote to win a seat. Thirty percent of the vote there yields about 45 of 150 seats. In an American House district, the same 30 percent can yield nothing.

The Case for a Threshold

Proportional systems carry their own risk: fragmentation severe enough to make governing impossible. Weimar Germany allocated one seat for every 60,000 votes with no minimum threshold. After the 1930 election, 15 parties held seats in the Reichstag, no stable majority could be formed, and the chancellor governed by emergency decree.

Postwar West Germany concluded that excessive fragmentation was itself a danger. Its successor system requires a party to win 5 percent of the national vote to receive seats from that vote, with exceptions for parties that win three constituencies outright and for parties representing recognized national minorities. The exception is why the South Schleswig Voters' Association, which represents Germany's Danish minority, holds a single seat in the current Bundestag. The threshold has a cost: in the February 2025 election, the Sahra Wagenknecht Alliance received 4.97 percent and no seats, and the Free Democrats received 4.3 percent, also without seats. Parties left below the line accounted for roughly one in seven votes.

The British Exception

Britain uses the same plurality system as the United States, yet sustains more than two significant parties, because geography can override Duverger's logic. In the 2024 general election, the Liberal Democrats won about 12 percent of the vote and 72 seats, while Reform UK won about 14 percent and five seats. Liberal Democrat support was concentrated in winnable constituencies; Reform's was spread across many seats where it finished second or third. The same concentration keeps Scottish, Welsh and Northern Irish parties in Parliament. Plurality rules do not eliminate every small party, only those whose voters are dispersed. Britain considered changing the system in 2011, when voters rejected the alternative vote in a referendum by 67.9 percent.

Why America Has Not Switched

Three obstacles stand in the way of proportional representation for the House. The 1967 statute requiring single-member districts would have to be repealed. The members of Congress who would need to repeal it all won their seats under the current rules. And voters have shown little appetite even for modest change: in 2024, measures to adopt ranked-choice voting, which still elects one winner per district, failed in Colorado, Idaho, Nevada and Oregon, while Alaska's existing system survived a repeal effort by 664 votes.

The Trade-Off

Each system trades one value for another. Plurality rules favor stability and clear accountability; election night usually produces a governing majority, but seat totals can diverge sharply from votes. In Britain's 2024 election, Labour won 33.7 percent of the vote and 411 of 650 seats. Proportional systems favor representation, but governments are assembled through negotiation after the vote. After the Dutch election of October 2025, forming a government took nearly four months, and the resulting coalition holds 66 of 150 seats with no support agreement from any party outside it. In the United States, the equivalent bargaining takes place inside the two major parties, through primaries; the Unite America Institute, which advocates open primaries, estimated that 380 of 435 House seats in 2024 were effectively decided at the primary stage.

The difference between 15 parties and two, in short, reflects not national temperament but the treatment of losing votes. Discard them, and voters consolidate behind two options. Count them, and smaller parties survive.