Australia has ranked choice and we also have a 2-party system for all intents and purposes. I don't think ranked choice is the answer, but the voting system (mixed-member proportional) used in New Zealand and Germany seems to be doing a much better job of getting a good variety of voices in their respective legislatures.

That is certainly true, and the downsides of a two-party system are not small. On the other hand, multi-party systems have a tendency to build less stable governments, which was one of the reasons for the downfall of the Weimacher Republik and the rise of the NSDAP.

With the addition of more parties to the German political spectrum, building coalitions has been harder in recent years, forcing essentially the two most central mainstream parties, CDU/CSU and SPD, to build a "great coalition". The problem of this is that people not happy with the results necessarily have to vote more extreme, and we did see a lot of protest votes, swinging from the very-left Die Linke to the ultra-right Afd, for example.

Observing the political process in the US, it seems that the primaries leave the final candidates always somewhat worse for wear, maybe more so on the Democrat side than on the Republican side (Infighting seems to be a worldwide phenomenon more prevalent on the left). By necessity, most winning candidates must then do a dance from the more extreme positions they expressed to win the primaries to the center. This is almost by construction, as the voters in the primaries will almost always be more extreme than the voters in the presidential election, even if reduced to those which would consider to vote for the party in the first place.

> On the other hand, multi-party systems have a tendency to build less stable governments,

That's the popular myth, based largely on a combination of conflation of parliamentary and multiparty systems (the two have no essential connection) and the fact that parliamentary systems tend to use different language around a government/administration than presidential systems do.

Measured by either cabinet or head of government turnover rates, multiparty parliamentary systems among established democracies are more stable than the US.

> which was one of the reasons for the downfall of the Weimacher Republik and the rise of the NSDAP.

Two party systems have at least as much problem (really, more) forming moderate-to-opposing extreme coalitions against extremists from one side, which is how extremists of the Right have progressively hijacked a major party in the US, with nothing like the level of externally-imposed stress that produced the NSDAP in Germany. [0] At least in a multiparty system, forming a coalition across tribal identity boundaries formed by party labels is expected.

[0] see, https://www.economist.com/graphic-detail/2020/10/31/the-repu...

The idea of a grand coalition _seems_ odd, because I think we’re all accustomed to our major political parties fighting rather than cooperating, but if they can work together isn’t that a rejection of extremism on both sides and an embrace of centrism, which, perhaps, is what the German majority actually want? I know very little about German politics so I’m just asking the question here - but I’m genuinely curious, what’s the downside?

For short term, I think these coalitions can work. But there are two problems: First, in a normal big party/small party coalition, the small party typically has a very specific agenda. For example the Green party with environment protection. So it's easy to make a combined program: The program of the big party + that special thing. With two "we do everything" parties, where each party wants to appear as "having made their mark", it's much harder to combine to a big program. And because everybody wants to leave their mark, there is a lot of fighting, so that in the next election, you can rule alone or with a small party, so you'll have more power.

Second: There will always be people not happy with the government. Maybe because they really got handed the short stick, or because they just tend to pick the short stick. That is true even if they are better off than before, just if other people are more better off, people will not be happy. These people want to vote for an opposition. Who should they vote for? They can only go to an extreme party.

> There will always be people not happy with the government.

> Who should they vote for? They can only go to an extreme party.

That is what extremists want you to believe. But the belief that both big parties are corrupt exists in the USA as well, and it helped Trump. The fact of the matter is, if you are unhappy with what a grand coalition does, you can still vote for the party that you agree more with to have it gain more power next time around. Only if you believe that cooperation and compromise themself are bad things, you have to vote extreme.

That is easy to observe in German politics. Yes, some people vote for the party they agree with more, but many do not. This has nothing to do with "the party is corrupt", but with "the party doesn't do what I want them to do".

Americans for some reason have fixated on FPTP as the cause of the two-party system and hope RCV/IRV will extract them from it.

The basis of a two-party system is actually single-member electorates. Because each seat can only have one representative and the economics of campaigning and organising make it hard for a third party to make appreciable inroads.

Australia's Parliament demonstrates the differences: the House of Representatives is composed of single-member electorates and is dominated by the two major political organisations (and this is for the good, as the government is formed in the House and a two-party system almost guarantees that a government can be formed and sustained easily after each election). The Senate, by contrast, is composed of multi-member electorates, one for each state, elected on a proportional basis. While the major parties typically have the largest share between them, the nature of a proportional multi-member electorate is that it creates more room for minor parties to obtain one or two seats.

Thanks for the thoughtful response. I agree that there are other structural challenges in the way of making additional parties really viable. My theory is that changing from FPTP would sort of break the ice and allow other parties to gain momentum, normalize the idea of other parties not being totally fringe, and maybe pave the way for some other enabling changes once it’s no longer strategically a terrible idea to vote for the candidates you prefer but almost certainly won’t win. It’s not the only change that would help, to be sure.

RCV/IRV does not this promote more moderate candidates, from any given party.

Agreed, plurality voting has to go. St. Louis just adopted approval voting [1] which is even better than ranked choice voting (no need to rank and avoids the non-monotonic problem of RCV). So things are looking up!

[1] https://stlapproves.org/

Why do Canada and the UK have more than two viable parties when they use FPTP?

Because people are failing to vote strategically. In Canada the 3 party system even more heavily favors the right (Conservatives), as our center-left parties (NDP, Liberal) are very similar and split the vote. In strategic elections this narrows considerably.

We also have a parliamentary system, where these parties can make coalitions and essentially pool votes, which softens (but doesn't eliminate) the need for strategic voting.

Canada has 5 parties. Bloc, lib, con, ndp and green not to mention another protest right party. A few years ago the cons were split into two parties.

Rarely outside of BC does lib-ndp vote split work in the con favour and often works the other way for the lib in Quebec with the bloc.

The ndp and lib seem like they are progressive and the idea that one should vote for the other to block the cons misses the differences. And your vote is worth a few dollars so vote for what you want... because funding matters.

That sounds more like an eventually 2-party system which hasn’t reached equilibrium yet. Granted, I know zilch about the rest of the voting system.

Neither Canada or the UK have a separate executive chamber that they vote for. The PM and his cabinet is 'just' a set of MPs that their own party delegated executive responsibility to.

POTUS, on the other hand, is personally entrusted with substantial levels of power.

Wrt Canada, because of Quebec. The bloc has an alignment that's neither liberal or conservative, and Quebec has a huge amount of seats.

It's very dubious as to whether the UK per se can be said to have "more than two viable parties".

The constituent countries each have a nationalist bloc that will often be successful in local government but not really at the UK level unless whoever is running the UK as a whole is antagonistic to the nationalist position. This results in silliness like Wrexham (which is technically over the border into Wales but nobody there speaks the Welsh language) being required to have Welsh-speaking bureaucrats and signs in Welsh even though the most likely language you'd hear there besides English is... Polish. Why do this? A few million quid on symbolic gestures defuses Welsh nationalism, cheap at twice the price.

But those nationalists won't work together and have almost nothing to say about the UK's larger politics. The closest is probably either the Scottish Nationals objecting to the consequences of Brexit (since Scotland didn't vote for it, and it destroys at least one of the claimed benefits of voting against independence for Scotland in its previous referrendum) or the DUP (a Northern Irish party which opposes Irish independence and is closely affiliated with the Conservative Party) offering a Confidence & Supply deal to keep the Tories in power.

Beyond that, there's the Liberal Democrats, but they aren't very big, and the only time Brits gave enough Lib Dem MPs the nod, they were obliged to throw their lot in with the Tories†, who aren't stupid and used this to ensure most of the blame for the resulting Tory policies landed on Lib Dem MPs who promptly lost in droves. They are nowhere close to being a "viable party" in the sense of able to govern, though they do have majorities in some local governments.

And then what, one Green MP? I mean, she's competent, her policies make sense, all credit to her, but on her own she is not a "viable party" in that sense. Her constituents (Brighton) are going to vote for her because they trend hippier than most of the UK (also gayer, but I don't think the Green Party is especially pro-LGBTQ), because she's good at her job and incumbents are always harder to defeat but that doesn't result in a Green UK government, just one MP.

So no, really there are two viable parties, the Conservative and Unionist Party (Conservatives, "Tories") or the Labour Party. I think they're both a bit screwed because they both subscribe to beliefs about the importance of Work and I believe we're at the end of the era in which the capability of humans to do Work is necessary or perhaps even relevant to prosperity.

† The existence of numerous smaller groups some of which I did not mention means that the Liberal Democrats could not have formed a working coalition with Labour, because that coalition would lack the votes to beat a "No Confidence" motion from Tories and other rival parties, forcing fresh elections. With the Conservatives they had more than enough, so the only alternative to a Tory coalition was fresh elections. In hindsight that would have been the correct choice perhaps, but wisdom at the time was that the one thing voters hated more than the other party was elections, so never force fresh elections unless you're confident you can win them.