As a Brit who for the first time has started following US politics, I cannot understand when it comes to choosing a President there is an option of only two political parties from who to choose from?

In the UK there are a vast array of political parties, spread right across the political spectrum. But in the US you have a choice between Democrats or Republicans, (although within each party you will have candidates or are either more right or left wing).

So how is it the US ended up with only two political parties from who to choose a President?

  • 8
    There are many political parties in the US. Commented Jun 8, 2016 at 15:26
  • 3
    Yes but they never get featured in news stories as putting forward a candidate for President. Commented Jun 8, 2016 at 15:28
  • 2
    It is an issue of the First Past The Post election method. Since only the most voted party gets the representation, strategic voting is encouraged (maybe you would want to vote, say, Socialist but you know they are not going to be the most voted party, so you instead vote Democrat so at least you avoid the Republican candidate winning). Since the minoritary parties do not get representation, their visibility/vote intention does not improve and the situation repeats itself at the next round of election. Check youtube.com/watch?v=r9rGX91rq5I
    – SJuan76
    Commented Jun 8, 2016 at 16:19
  • From my transatlantic perspective, looks like they should have had Richard Pryor's None of the above party....
    – Phil Lello
    Commented Nov 26, 2016 at 20:02
  • 1
    @DarthVader It is a bit funny to say that in the UK one has a vast array of parties. If the UK had a proportional system, then that probably would be the case, but there are basically two parties excluding regional ones. It is almost a miracle that you have Lib Dems represented. Commented Mar 30, 2022 at 15:18

3 Answers 3


As others mentioned, this relates to how first-past-the-post voting works with the presidency. Duverger's law says that the voting for any single post will devolve to two parties. This happens because tactical voting means that people will tend to vote for the lesser of two evils rather than the third party that has no chance.

Now, you might immediately point out that the United Kingdom (UK) has both first-past-the-post voting and more than two parties. The difference is that in the UK, there is no single election that forces voters to align into two parties. Instead, each seat in parliament is a separate election. Most seats will still only have one or two serious candidates. But a third party can participate because of support from other seats where they are more serious. After the election, the parties can team up to form a government.

In the United States (US), the presidential candidates run directly. If a candidate wins, that person becomes president regardless of the results of the legislative elections. For example, the Democrats held the House of Representatives continually from 1958 to 1994, but during that time, Republicans held the presidency for twenty-two of the thirty-six years.

It's also worth noting that in that period, there were three different major third party attempts: George Wallace (1968); John Anderson (1980); and H. Ross Perot (1992). But it's hard for a failed party to persist. By their nature, presidential campaigns are national. Of those three, only Wallace was regional. And he didn't take his legislative supporters with him, as they would have lost the benefits of support from their existing party.

You might contrast that with how things work in the UK. A regional party (e.g. the Scottish National Party or SNP) can immediately join either the government or the opposition. In the US, a candidate in such a party would lose the advantage of presidential endorsement. Because presidential campaigns are national, they compete in each congressional district. So the party can support a candidate trivially by adding the candidate to the ticket. In the UK, the legislative candidate would head such a ticket in most places. In the US, it's the president.

Is it impossible to have a third party in the US system? Certainly not. Look at the 1860 election. Prior to that, the Democrats and the Whigs were the two parties. After that, the Democrats and the Republicans were. But note how everyone still picked sides. They just changed the alignment.

Lesser changes happened in other elections. Wallace took his voters away from the Democrats in 1968, and the Republicans won five of six presidential elections. Perot took his voters out in 1992 and Democrats won a plurality of the popular vote in five out of six presidential elections.

Things may not be as different as they first seem. Yes, parliament has multiple parties. But when was the last time that the prime minister was neither Labour nor Tory? Your prime minister is also chosen from just two parties. The difference is that your politicians can form alliances after the election while in the US, voters have to figure out alliances before the election. So our versions of Arlene Foster and Gerry Adams join one of the existing parties before the election rather than forming coalitions with them after the election.

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    " Look at the 1860 election. Prior to that, the Democrats and the Whigs were the two parties. After that, the Democrats and the Republicans were." Seems more similar than different to how Britain had Liberal and Tory before Labour and Conservative.
    – user8398
    Commented Jun 9, 2016 at 14:39

The answer regarding first-past-the-post is an important one. However, it's also important to note that there are extremely onerous signature-gathering requirements in order to get ballot access for parties other than the big two.

Jacobin looks at the issue in the context of American labor party politics, noting for instance that to get on the ballot in California, a party must get signatures totaling 10% of the prior gubernatorial vote. The New Republic also talked about the challenges of third-party ballot access, though with a focus in this case on the lack of space for a "centrist" party.

For a more just-the-numbers source, see BallotPedia's review of the signature requirements for independent-candidate ballot access in the 2020 Presidential election. This book also appears to offer a more academic take on the broader issue of partisan influence on election administration (note, I haven't actually read the book, it just looked relevant, retweets are not endorsements, etc).


I would largely pin it down to the rule that third parties have to get more than 5% support in order to qualify for mainstream media coverage and to be included in cross debate with the Reps and the Dems during election time.

It's amazing how many Americans think they only have 2 choices and the rules ensure that illusion exists

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