When do political parties split? Answer lies in diverging voter interests

When voter interests diverge, parties split. If space allows, both survive. If not, only one remains

Why do political parties split — or stay together? For most of us, the obvious and intuitive approach to party politics is the following: Parties represent a relatively cohesive bloc of voters who are aligned by material interest, or regional or community consciousness, or economic ideology. When the interests of some of these voters diverge from others, then parties split. If there is space in the polity for an additional party, then both survive. Otherwise, only one does.

The British parliamentary system, the ancestor of most other legislatures, demonstrates this quite effectively. There is space for two large parties and one or two smaller ones in the mainstream of English (and therefore British) politics, alongside three regional parties representing the smaller nations in the United Kingdom. Parties — particularly the Labour Party — have split in the past few decades. In the last decade alone, some prominent centrists abandoned Labour during the years the left was in the ascendant in the party, and created a new bloc. It did not survive. A previous generation of centrists split off in the early 1980s to create the Social Democratic Party, which eventually had to merge into the third-party Liberals to create today’s Liberal Democrats. These cleavages were driven by clear ideological differences and are relatively easy to understand.

But other polities can be dramatically different. Consider Ireland, where power has been divided for decades between two parties -- but which barely seem to have any ideological differences. Both Fianna Fail and Fine Gael are right-of-centre; their differences were born a century ago and now — to unsmiling, non-Irish eyes — appear not to be large enough to sustain a two-party polity. Unsurprisingly, a third entrant — left-wing populist Sinn Fein — is now large enough to challenge the centre-right duopoly.

This week I was reminded of the puzzling nature of party politics when Japan was informed it had a new Prime Minister, following a bruising campaign within the ruling Liberal Democratic Party (LDP). The right-wing LDP has been dominant in post-War Japanese politics, with the Opposition barely getting a few short spells in power. Absurdly, however, intra-LDP politics can be every bit as bruising and bitter, if not more, than inter-party politics. The party even has, or had, an organised system of “factions” often associated with specific ideologies and personalities. These factions have their own histories, divisions — and scandals. To non-Japanese eyes, it is as if there are two different party systems here — an uncompetitive, formal system for elections to the Diet, and a competitive but informal system within the LDP that determines which faction is dominant.

Why the LDP has not split, or why any breakaway factions have not coalesced into a “normal” two-party polity, is hard to understand outside Japan. Certainly, it has had major crises — during the “40-day war” in the 1970s one faction barricaded itself within party headquarters — but it has remained a single, formal bloc and politically dominant through all of them.

In some sense, for Indian eyes this system is as if the Indian National Congress (INC) had never split in the 1960s, and replaced its post-Indira Gandhi framework with a factional system in which various successors of the Syndicate leaders competed to win the favour of party members. It is not impossible to imagine this, but it is not clear how it could have been stable for decades. The split of the dominant party of the freedom movement a few decades after its purpose was achieved, and the rise of alternatives — representing the dominant small landowning castes (Janata and its successors) or Hindu nationalism (the Bharatiya Janata Party, or the BJP) and finally regional aspirations (the Dravidian parties and the Trinamool) — seem almost inevitable to us.

A natural experiment on such inevitability is occurring in South Africa. The African National Congress (ANC) — which shares multiple similarities with the INC in its origins, purposes, organisation, and fuzzy ideological nature — is convulsed with internal tension. A former leader, Jacob Zuma, has created a powerful breakaway party, which has a populist agenda at odds with that of the grandees who remain in control of the official ANC. Blocs within the ANC — economic nationalists, pro-business moderates, and others — have different visions of the country’s future. Ethnic and regional parties —representing the Zulu ethnicity, or drawing strength from more English-speaking and White-dominated parts of the country such as the Cape Province — are growing in power as local challengers or influential coalition partners.

India, it seemed for a while, was going in the opposite direction. We were promised a “Congress-mukt Bharat”, indeed an Opposition-free polity, and it really seemed that was achievable. But it seems countries like Japan are unique. People want party politics even if the differences between the parties are slight, as in Ireland. A one-party BJP-dominated polity would merely have opened up space for splits within the new establishment, the way the Congress of old disintegrated.