Two-party politics used to be the norm for developed democracies. Most countries' politics were divided between tribal blocks based on the urban working class and on the aspirant middle classes. But the dominance of these two blocks has faded in most countries. There are two interesting exceptions: the USA and Australia. Here in Britain two-party politics looked as if it would triumph with the demise of the Liberal Democrat,s and the No vote in the referendum on the Alternative Vote (AV) in 2011. But now the system is its death throes.
It is worth considering the architecture of two party politics for a moment. Electoral politics is dominated by two political parties, each of which may govern on its own, without the need for support from smaller parties in coalitions or pacts. Each of these parties has a tribal character, defining themselves as much in opposition to the other as by their own core values. But there is an undeniable class base two. This divides the country into heartlands, where one or other of the parties dominates to the exclusion of all others, and marginal territory, contested by both parties, where elections are won and loss. Many, if not most, politicians build their own careers in the heartlands, where advancement depends on internal party politics, rather than winning over marginal voters. This leads to the system's major flaw - the political classes are more worried about their own backyard and internal politics than in appealing to the electorate at large. Or they worry about marginal voters to the exclusion of the heartlands. Distance between voters and politicians grows.
The breakdown of this system follows the weakening of class loyalties from the 1960s onwards. New parties have emerged, from the liberal centre, from populist anti-political movements, from environmentalists, and from parties based on regional identity. In much of Europe coalitions became commonplace. Electoral systems played an important role. Those with proportional representation (PR) were the first to find that one party could not govern on its own. But in countries with single member constituencies one party could still aspire to win on its own. France's two-round system promoted pacts and alliances between parties, and the major blocks split into separate parties - before the whole system started to be challenged by the populist Front National. Countries with First Past the Post (FPTP) systems have placed a greater role on party solidarity. But in New Zealand disillusion with two-party politics led to the introduction of PR; in Canada each of the two party blocks suffered existential crises that allowed more modern alternatives to replace them, at least in part. Australia's AV system seems to have entrenched the two party system there, however. I will come back to that.
In the biggest and oldest developed-world democracy of them all, however, the two party system remains completely dominant. In the USA there is no alternative to the Republicans or Democrats, although the occasional challenge comes and goes - even as more and more voters self-describe as Independent. But the US system of democracy is unique. Apart from the widespread use of FPTP (some states use a two round system - which is why the Louisiana Senate race is not yet over after this month's nationwide election), I think there are three, inter-related factors: primary elections, decentralised power, and direct executive elections. Each party's candidates are selected using primary elections which include much more than official party members. Such elections are part of the formal, state electoral process. Voters may register as Democrat or Republican. This allows them to take part in publicly-run primaries; in some states primaries are open - any voter can take part. That makes heartland elections competitive - and not a matter of manipulating small groups of insiders to secure your party's nomination. It helps that each party's national leadership is weak - so wheeler-dealing in Washington will not help a political career by much. This is a function of a system where much of the power is wielded at state level. One of the factors that keeps party functionaries weak is the prominence of direct executive elections, notably for President and state governors. In these cases personality often matters more than tribal allegiance.
It is an interesting paradox - for the two party system to be robust, the party leaderships must not be too strong. This allows the primary system to flourish, and gives outsiders a chance to break into politics. But party solidarity is important enough for those in power to rig the system to provide incumbent politicians with electorally safe seats through the gerrymandering of boundaries. A diminishing proportion of seats in the House of Representatives are competitive between the two blocks. A large proportion of the important politics is now in the tribal heartlands, and not in marginal territory. As a result of this, it would not be right to describe the state of politics in the USA as healthy. There is increasing polarisation, which is causing deadlock and the prospect of extremist policies. Most Americans seem fed up with the state of politics in their country, though not necessarily with the system itself.
Another case study in the survival of two-party politics is Australia. Politics is divided between two long-standing political blocks: Labor and the Liberal party, though the latter is a coalition of state parties (some of which refer to themselves as National or Country). There have been challenges to this duopoly over the years, but these have not made headway. No doubt there a number of factors that have contributed to this - but I think one factor is critical. And this is the AV electoral system. The legislature comprises single-member constituencies, and there is a single election day. Voters are asked to rank candidates in order of preference. If one candidate does not achieve more than 50% of the votes casts, the lower ranking candidates are eliminated and their votes redistributed. This is a bit like the French two round run-off system, except that with a single election day there is little scope for political deal making over second preferences. It is so important for candidates to maximise first preferences that it best not to talk too much about second preferences.
This makes it very hard for challengers to win seats. First their first preferences have to overhaul one or other of the two main parties. But to do so they cannot say "vote for me to keep the other guy out", because that is an argument for second preference votes, not first. Second preference votes are useless without sufficient first preferences. And then, of course, you must have sufficient first and second preference votes to get a majority. In marginal seats challengers will be beaten by the lack of first preferences; in heartland seats there will be lack of second preference votes. As a result almost all seats go to one or other of the blocks. In 2013 in order to turn out a lacklustre Labor government, voters opted for a Liberal one that is now pushing forward a series of extremist policies on the environment and immigration.
So what of Britain? For a long time the main challenge to the two party system came from the Liberal Democrats, based in the liberal centre. It was skilful in winning seats under FPTP by establishing a local base, and then winning tactical votes from the weaker of the two blocks. This allowed it to win a substantial block of parliamentary seats in 1997, but not the balance of power until 2010. It then entered coalition with the Conservatives. And then disaster struck - the transition from a protest party to one of government was too much for the voters, and its poll ratings collapsed. Labour and Tory politicians breathed a sigh of relief - normal two-party politics could be resumed.
Ironically, in view of the Australian experience, the Lib Dems placed some hope by proposing to change Britain's FPTP system to AV. This would have helped the party in the short term, where it had built up a sufficient local base to win second place in first preference votes. Both major parties agreed with the Lib Dem analysis, and for that reason opposed the change (Labour through faint praise rather than explicit opposition). In a referendum on the change in 2011 an overwhelming majority opposed AV. This seemed to secure the future of two-party politics.
But unlike the US, Britain's politics is highly centralised. Party managers in Westminster like to keep a tight grip on their parties. And, again unlike the US, executives are elected indirectly, and candidates must master the internal politics of their own party in order to progress to high office. The idea of primary elections has not been allowed to gain traction. The Tories have moved small steps towards it, but without being able to harness state resources. The public has no way to channel its disillusion with politics than to vote for insurgent parties - since they are denied a role in the main party elections. And this they have been doing by supporting the populist Ukip in England and the SNP in Scotland.
Unlike the Lib Dem challenge, these insurgencies have affected the main parties' heartland voters. They are creating unbearable pressures with both party blocks. The Conservative and Labour leaders try both to fend off the insurgent challenge, and to retain the political centre - and as a result both appear weak, driven by events rather than leading them. This is creating unbearable strains and it seems likely both will fracture, especially if they have to endure the pressures of being in government. Labour face calamity in Scotland, as the SNP overturn their heartlands. In England Labour are a fragile coalition of public sector unions, liberal centrists and heartland machine politicians; each's expectations of the party seems completely incompatible. The Tories look likely to fracture over Europe.
Ironically, if both parties had embraced AV, they would have been in a stronger position to fend off the insurgents and maintain party solidarity. And yet this is just another face of a bigger problem that both party's face. their obsession with winning the next election has meant a loss of strategic focus. The demise of the two party system looks alarming, as fringe parties gain prominence. But in the long term it is to be welcomed. As the USA and Australia shows, a two-party system is too easily captured by political extremes.