Most countries with multi party systems use different methods for selecting their representatives. When you do a straight aggregation of geographical areas in which you take whomever gets the most votes in each area (sometimes called first past the post) it becomes possible for the most disliked party in a country to win, widely geographical distributed concerns (like ecological concerns) become underrepresented, and most relevant to this conversation, having multiple parties that are close to each other is a huge disadvantage compared to having a single party attracting more people. Because of this, countries with this system will usually see smaller parties merge and stabilise on a 2 party government / opposition set up.

The study of how different kinds of voting systems work and their advantages, disadvantages and consequences is called social choice theory. There's an interesting theorem called Arrow's theorem that proves that given a certain set of assumptions, there can be no voting system that works exactly as we would like. Sometimes this is used to argue that all systems are equally bad, but I think this is not true at all - even while imperfect, some systems are much better than others.

You remind me of Veritasium's video [1]. I should rewatch it and pay actual attention.

[1] https://www.youtube.com/watch?v=qf7ws2DF-zk

Not a direct cause but popped into my head:

Previous to 1988 the League of Women Voters[0] handled presidential debates. A fully independent outside organization.

Since then, the Commission on Presidential Debates[1] set rules for admittance to president debates. The CPD was founded jointly by Republicans and Democrats and is controlled solely by both parties.

At best, there _appears_ to be a large, gaping conflict of interest when it comes to admitting candidates to presidential debates. In 1992 Ross Perot was invited to the debates as a third option. In 1996 Clinton and Dole successfully argued for Perot to be excluded from the debates as he had no "realistic chance to win" [2]. Perot aside, what happened was downright anti-democratic and further enforced the two party system.

---

[0] https://www.lwv.org

[1] https://en.wikipedia.org/wiki/Commission_on_Presidential_Deb...

[2] https://www.washingtonpost.com/archive/politics/1996/09/18/p...

Beyond that, a quirk of the American system in many states is registering your party affiliation at the time you register votes so that you can participate in primaries. When you've got >45% of registered voters identifying as being a supporter of one of the major two parties closely enough to add it to their name on the electoral roll, it's not exactly an encouraging environment to break that status quo

Other majoritarian democratic systems often also converge into two party (or two and a bit party, or two parties per region systems) but few seem to normalise voting for the same party every time in quite the same way.

To further add to that, many states do closed primaries. If a voter isn't registered with one of the two ordained parties, they realistically cannot participate in primaries at all.

If there would six parties to choose from, for example, I think it would be hard to argue that closed primaries are harmful. But since we have a duopoly, they exclude a significant portion of the voting population from participating until late in the process.

> If there would six parties to choose from, for example, I think it would be hard to argue that closed primaries are harmful.

Six is a not-uncommon number of parties qualified for ballot access in a US state, though some have fewer and some have more.

https://ballotpedia.org/List_of_political_parties_in_the_Uni...

there is roughly 0.000087% of US population who can name more than two

The debates are a distraction, the issue is the electoral system (and, at that, mainly the electoral system used for state and federal legislative elections), not the system of admitting candidates to Presidential debates.

First-past-the-post tend to lead to two-party systems while proportional representation tend to lead to multi-party systems. But you can’t have proportional representation in presidental elections since only one candidate can win. Countries with multi-party systems tend to have parlimentary systems.

And yet the French somehow manage to have a multi-party system while citizens directly vote for the president. And they also have a parliament, as does the USA.

Because they can have two rounds of voting: the first time you vote for who you really want, the second time you choose the lesser evil

> And they also have a parliament, as does the USA.

A "parliamentary system" is not about just having a parliament (an elected legislature), it is a name for a system where the elected parliament is the paramount power in government, including choosing the head of government. The French have something close to that, the US does not.

The French have a semi-presidential system where, as in a parliamentary system, the head of government is the PM elected by the parliament and formally appointed by the President who is the head of state, the US has a (very strong) Presidential system, where the President is head of government (as well as having a Presidential election system that, even ignoring the role of the President, inherently favors duopoly more than the two-round French system.)

The executive body in Switzerland has members from 5 different parties, but it's elected by the federal assembly, not directly:

https://en.wikipedia.org/wiki/Federal_Council_(Switzerland)

Its not really an "election" since they have to stick to the Zauberformel and reproduce the results of the parliament.

The only elective part is which "faction" of the party the person will be coming from, i.e "Zürich"/"Bern for UDC/SVP.

That question got a downvote? I wonder why. It's a genuine question. Why can't good faith be assumed?

Edit: I get that people downvote this comment since it's always controversial to ask.

I personally always ask when I am more curious about the answer and am willing to burn any potential karma over it.

Asking for feedback is more important.

I'm just genuinely surprised about the other one.

I appreciated your question. I don't really know the answer, and I grew up in the USA. Maybe someone took it as a rhetorical question?

The early USA gave rise to a party known as the Democratic-Republicans which had the critical mass of officials and candidates to rival the Federalists and eventually dominate them so badly that by 1824 no opposing party even had a candidate for President. There were actually 4 candidates on the ballot though, but they were all from the same Democratic-Republican party. In that case none had enough electoral votes, so Jackson won that one when it was decided by the House. He had a total nationwide popular vote of 151,271, so you have to figure that each vote had so much of a stronger voice back then under a system quite similar to today. Unless you were there I don't think the difference in scale would be easy to fully comprehend. The party was supposedly doing well in lesser races across the growing US too.

https://en.wikipedia.org/wiki/List_of_Democratic-Republican_...

Then apparently the party just kind of split up and re-organized into the "two-party" system that has continued to dominate ever since.

There was no threat until decades later when the Free Silver parties arose based strongly on reversing the trend where increasing economic opportunity was being systematically pushed further beyond reach of average citizens, in the face of bonanza precious metal discoveries that would have been able to pull the whole population ahead of Europe decades sooner if the Free Silvers would have had their way. Bipartisan effort was resurrected as if from a single party again, and the third party was crushed by a well-maintained machine which was bigger than either one of the major parties on their own. Before the citizens could be allowed to get a little taste, the Silvers were assimilated by the Democrats in a platform expansion that was over-dramatized but badly diluted their objectives. It does seem to be the first real big platform deviation between the Democrats & Republicans to start off the 20th century with, but the Silver supporters continued to be systematically disadvantaged for decades to come.

No third party movement has presented that level of threat to include such economic clout, but if so, deeply rooted underhanded countermeasures would be deployed, it would apparently take more than anyone could imagine, so no third party for you.

> The early USA gave rise to a party known as the Democratic-Republicans which had the critical mass of officials and candidates to rival the Federalists

The Democratic-Republicans formed before the Federalists, actually.

> There were actually 4 candidates on the ballot though

Unlike the modern system, there weren't even ballots in a quarter of the states (a popuar election for electors is not a Constitutional mandate, and it wasn't a statutory requirement to have such an election for a states' electoral votes to be considered regularly-given until much more recently.)

And the candidates weren't on the ballots that existed, party electors were (unlike modern ballots, where the Presidential candidate is listed and you get the associated electors if they win, the actual electors -- and not usually the candidate they were pledged to -- were listed on the ballots, where they existed.)

And in most states, there were not electors for all four candidates on the ballot, the four are just the candidates that received electoral votes from somewhere in the country.

> In that case none had enough electoral votes, so Jackson won that one when it was decided by the House.

Jackson won a plurality—but not the required majority to win outright—of the electoral vote, but the House elected John Quincy Adams in the contingent election required to resolve the absence of an electoral vote winner, not Jackson.

> He had a total nationwide popular vote of 151,271, so you have to figure that each vote had so much of a stronger voice back then under a system quite similar to today.

As discussed above, the system was not "quite similar to today".

> Then apparently the party just kind of split up and re-organized into the "two-party" system that has continued to dominate ever since.

The new Whig Party which was its initial main opponent did form in part from dissident offshoots of the Democratic-Republican Party, but a lot of its strength was from bringing in existing regional parties that were never competitive national parties (like the Anti-Masonic Party) as well.

> There was no threat until decades later when the Free Silver parties arose

Kind of leaving out the entire rise of the Republican Party and the displacement of the Whigs...I could go on with responding to the blend of oddly selected facts and complete distortions, but I'll just note that it doesn't get better.

Good to see more details giving insight into how things got to be the way they are.

What do you think it would take for a third party to become viable over the short term, and what would inhibit or enable them to become a contender?

The European systems, I'd argue are absolutely worse than many of the "direct republic" systems in the US and other American countries because in the European systems there's a pretense of "consensus" reaching and it mostly ends up preserving an elite status quo and hiding any problems. That's why there's such a big tendency of nanny stating and censorship. It's entrenched in a bureocratic way.

The direct vote gets a better chance at subverting the system radically and that's a good thing. Regardless of criticism from the losers about "populism". The end result is great for democracy and actual change.

Because the legislature uses single member districts with essentially either majority, plurality, or some form of two-round runoff elections, and the executive uses indirect elections where the electors are (for the largest part) elected as statewide at-large slates by winner-take-all plurality. This makes, outside of very unusual circumstances, voting for other than one of the two leading parties ineffective in the normal case, and where it has any effect most likely it will shift the result from the least-unacceptable of the major parties to the most.

Many European countries use varieties of proportional representation (most commonly either party list proportional or mixed member proportional), and have a parliamentary system (so that there is not a separately-elected executive administration -- there may be an elected President but they tend to be a head of state and not head of government -- whereas in the US the executive election is even more heavily tilted to support two-party dominance than the legislative system, though the legislative election system is still the more important piece of the problem.)

While I normally keep the political threads at arms length, this is an interesting enough game/voting-theory question that I'm honestly surprised no one has linked the fact that this is a well-studied effect, to the point that it has a specific name: Duverger's Law. [0]

[0] https://en.wikipedia.org/wiki/Duverger%27s_law