If there's one thing this forum loves arguing about, it's political systems, so here's a question for you guys:
What would be the best/easiest/most interesting/??? way to ensure a democratically-elected government would have no political parties at all? If that's not realistic--certainly it makes sense for like-minded politicians to work together--then at least to result in a variety of political parties instead of just two major ones dominating everything.
Basically I just want to avoid a situation where it'd be likely only a very small number of parties matter for this concountry.
- alternate voting system (e.g. multiple rounds of voting or something)
- banning political parties?? (this seems unlikely to actually get rid of them in secret)
- historical tradition (also seems unlikely to persist for the long run)
- ...that's all I got.
The key here is something called Duverger's Law, which says that plurality elections tend to result in two-party systems. However, the converse is not necessarily true. In an ordinary system, to have more than two parties you need two phases...
First, you need a society that wants
more than two parties. The maximum sustainable number of (real) parties is generally the number of cleavages
+ 1. A cleavage is a division of society into two large parts with fundamentally differing values and priorities - people on one side of a cleavage oppose the people on the other side, and will if necessary unite together to oppose them. There is generally one major cleavage, and in some cases there may be other cleavages too. The big cleavage is typically class: rich vs poor. Rich and poor people have very different interests, so find it hard to compromise, particularly on economic policy. Other cleavages have included religious vs secular (eg France in th 4th Republic), one religion against another, urban vs rural, one region against another, one ethnicity against another, and so on. [there are cleavages on every issue, but only when lots of issues line up do you get society-wide cleavages that are politically significant.]
Sometimes cleavages are a little harder to get to the bottom of. For decades now, there's been excitement about the emergence of a new division - first in Europe, but now (thanks, Trump and Brexit!) in the UK and US too, between postindustrialists and postmaterialists. The former tend to be more socially isolated and anxious, often associated with the manufacturing sector and with economic decline; the latter tend to be more socially connected and optimistic, often associated with information-based and creative jobs.
But anyway, the point is: if you want lots of parties, first you need to have lots of division and argument.
Next, you need to NOT wipe out those potential parties through your electoral system. The more votes your system ignores, the more it will tend toward two parties: because people won't "throw away their vote" or "split the vote" and let the enemy sneak through. Simple plurality (first past the post) ignores about half of the votes cast, which are either for the losing party in a constituency or for the winning party that would have won without that vote. The former are particularly important here: if my vote for X party is certain to have no effect, but my vote for Y party might at least stop Z from winning, I'm likely to vote Y, not Z. And if we all know that, then X has no chance (even if X gets really popular it may take a long time for this to result in seat wins, until people realise it).
What you need at the very least is a two-round majoritarian system. This allows you to vote for X in the first round without jeopardising the effort to stop Z, because Z only wins in the first round if they get more than 50% of votes. This allows for the occasional moment when X does better than expected in the first round and ends up winning in the run-off. the FN in France, for instance, has been helped by elections where one side (usually the left0) has fractured, letting the FN into the second round, with all the oxygen of publicity that that entails - famously that happened in the presidential elections of 2001 (was it?).
Better, though, is a proportional system. In proportional systems no votes are wasted, or very few - unless there's intentionally a limit imposed on small parties.
[generally systems are set up to discourage parties, not to encourage them, because systems with lots of parties tend to collapse.]
Specifically, you want the most proportional system you can get - Saint-Lague (unmodified) or Hare (which looks like Saint-Lague in almost all cases but sometimes throws up paradoxes). [Saint-Lague is never actually used, because of this problem of encouraging multipartyism - instead, "modified" Saint-Lague is used, which makes it more moderate]. You want no formal thresholds (eg many countries don't give seats to any party who can't clear 5% of the vote), and you want the whole country to be a single constituency, preferably with ten million MPs (reducing district size and reducing legislature size both are mathematically identical to introducing a formal threshold).
You also need to avoid powerful presidents. Presidential races are inherently winner-take-all, which encourages two-partyism. [the core of Duverger's Law is actually that for most electoral systems the number of viable parties tends not to exceed one more than the number of seats available in each constituency; so a 1-winner election almost always has only two (viable) competitors]. This is particularly true of plurality elections, but it's also true even for majority (runoff) elections. The result of this isn't necessarily to create an official two-party system, though it can help in that regard, but it does tend to cause the political parties to align into two 'blocs'. This is particularly noticeable in France, where for most of the Fifth Republic there have basically been two disorganised parties, the Left and the Right, who happen to contain a shifting (and self-re-naming) collection of actual legal parties.
Indeed, this tends to be the case even in parliamentary systems, because the concept of government inherently creates a pressure toward two-partyism. The government wants to do X - do you agree, or not? Yes/no. Over time there tends to develop a bloc who support this government and a bloc who oppose it, and when the other bloc wins then the roles swap around. [sometimes there is a bloc who support the government, and an array of parties who oppose it who can't organise a single coherent bloc. This is very dangerous, and results in one-party rule for long periods of time.]
So ideally, minimise the government/non-government distinction. An example here is Switzerland. Their government is seven people (the official 'presidency' rotates automatically among them), and it functions by essentially avoiding democracy as much as possible: four major partie have agreed to form a coalition government. The coalitiong between the CVP and the FDP has lasted since 1891; the government has never, in 150 years, been voted out, and only four members have ever been replaced due to an election. Between 1959 and 2003, the government consisted of exactly the same ratio of party members: 2 CVP, 2 FDP, 2 SP, and 1 SVP, completely ignoring the various elections that took place in between. The Swiss idea of a political earthquake is that in 2003 the formula was finally changed from 2:2:2:1 to 1:2:2:2. Having the four major parties all be in government has massively weakened the them/us government/opposition dichotomy, and there are 8 opposition parties as well, but all are small, and all but two have 2 or fewer seats in the legislature.
That said, SP doesn't automatically mean only two parties. There are sometimes 'two-and-a-half' systems instead, with a small third party, like the Lib Dems in the UK. These typically merge into one of the big parties - like the way the two right-wing parties have effectively merged in Australia, or the way the Co-Operative Party has been reduced to a technical appendage of the Labour Party in the UK - but survival is possible, in theory. These will to some extent be regional parties, either officially, like the Bloc in Canada, or unofficially, like the Lib Dems in the UK: traditionally the UK can be divided into different areas each with a two-party system (the Lib Dems survived because of regional strength in the southwest and scotland, and the weakness of labour in places like the southeast).
sometimes a region can be so politically distinct that it has its own set of parties, like Northern Ireland. It has lots of parties because of STV, but also because mainland parties have traditionally avoided competing there, not wanting to sully their reputations in the rest of the country.
Then there's the possibility of avoiding parties altogether, or at least avoiding big parties. There are two obvious possibilities here.
One is a politics of so-called "notabile" politicians: locally famous people who attract personal loyalty from the voters. This is associated with young democracies, and also with very, very small democracies, such as the democracies of the pacific island nations. It can occur with any electoral system, although of course those that are based on individuals rather than parties are best in this respect. So SP, or STV, or PR with panachage.
[Again, notabile tend to be seen as a bad thing, since they encourge politics based on charisma, clientelism, and existing undemocratic power structures.]
The other is that where you have a sufficiently massive or disunited country, you can effectively have different political systems in different parts, yielding a multiparty system at the national level. An example here is the US. Traditionally it was said to have 100 political parties: because the "Democrats" in Alabama had no more in common with the "Democrats" in Massachusetts than they did with the "Republicans" of Alabama, and the Republicans weren't much better. If you look at how people voted in Congress prior to recent years, it's usually been the case that Democrats from certain states have been further to the right than Republicans from certain other states. Which is why Congress as a whole was so moderate, and why so many votes didn't go along official party lines (and why supreme court picks didn't get fillibustered and the government didn't keep getting shut down, etc). For several decades it was even more extreme, to the extent that political historians often track "Southern Democrats" as effectively a third party. Gingrich was the first to launch a real national manifesto (though there had been attempts before).
A more extreme version is India, where each state has its own party system, and the parties don't even share the same names. It tended to result in a one-party state, because the Congress was the only party (or coalition) able to unify enough local politicians to be a unified naitonal force. This, however, has also trended toward two-partyism, and it's moving toward being a two-way Congress vs BJP fight throughout the country, even if they go by different names in different places.