In 2015 Labour went for austerity-lite compared to Osborne’s full on austerity. It failed. Yet in 2017 Labour went for Brexit-lite, and it worked. Why does capturing the middle ground (often called triangulation) sometimes work and sometimes fail?
The theory behind why it should work is straightforward. Suppose you can grade an issue from 1 to 10, and we have a two party system: you can vote Labour or Conservative. In the case of Brexit, 1 would be staying in the EU and joining the Euro, and 10 would be No Deal. Now suppose voters are evenly distributed along this spectrum of possibilities: 10% want No Deal (10), 10% want a deal where we leave with minimal trade deals with the EU (9) and so on. An even distribution means 50% of the population want options between 1 and 5, and 50% want options between 6 and 10. Suppose the Conservatives go for option 8, which in this case is a fairly hard Brexit. Suppose Labour actually believe in option 3. What option should they campaign for in an election?
If all voters are well informed and are certain to vote, and there are no third parties, the answer is to go for the middle ground. If they campaigned for 3, they would capture only 50% of voters (those who prefer options 1 to 5), and the Conservatives would win those preferring 6 to 10. But if they campaigned for option 7, they would capture 70% of the vote. Indeed those voters who understood triangulation might have reasoned that although Labour were campaigning for 7, they were only doing that to appease some of their traditional core voters, and if elected they would actually go for a more EU friendly option.
You could read Labour’s position on Brexit in GE2017 as being very close to the Conservatives. But the language that stressed the importance of the economy allowed those who prefered options 1 to 7 to think Labour would be better than the Conservatives. Labour did indeed appear to go for something like option 7 in GE2017, and it seems to have worked: the swing to Labour was higher in areas that voted to Remain (their did not alienate voters who wanted options 2 or 3), but they captured some Leave voters as well. Whether that Labour positioning was based on triangulation or did actually reflect the leadership's true beliefs I honestly do not know.
Compare this to the 2015 election and austerity, where option 1 is wanting fiscal stimulus and more public investment because interest rates were stuck close to their lower bound, and 10 was an even sharper austerity than George Osborne was proposing. Instead he proposed option 8, and Labour went for something more moderate: on paper maybe 6, but they kept quiet about the difference so maybe in practice 7. Labour’s positioning is generally thought to have failed. Not only did they lose the election, but afterwards an ‘outsider’ became party leader on a platform that was clearly anti-austerity.
So why did triangulation work with Brexit in 2017 but fail with austerity in 2015? There are many ways of changing this very simple model to resolve this puzzle. My current favourite is as follows. What is missing from the linear scale of options outlined above is any account of the framework by which voters judge competence, and the option of not voting. In 2015 the dominant narrative was the one set out by the Conservatives: austerity was required because they were clearing up the mess left by Labour. By positioning themselves as austerity-lite Labour in effect did nothing to challenge that narrative. This had two consequences. First, those who took a strong anti-austerity line might have been tempted not to vote. Second, those in the middle did not go with Labour because Labour’s competence was questionable: they had caused the deficit problem in the first place.
So Labour’s positioning in 2015 to capture the middle ground failed. By not challenging the dominant narrative they appeared to accept their alleged past incompetence, and committed anti-austerity voters may have not turned up. In 2017 Labour openly challenged the austerity narrative. That meant they didn’t capture the middle ground, but they did not lose it either. (It should also be added that the middle ground on austerity has probably been shifting as the deficit itself falls.)
In 2017 with Brexit, there was no dominant narrative. As I have remarked before, the country is as divided as it was in the original vote. Labour had two options. It could oppose Brexit, and get the anti-Brexit vote. Or it could attempt to capture the middle ground by accepting Brexit but stressing that they would put the economy first. They, by preference or design, went with the second triangulation option and it seems to have worked.
Why were hard line Remainers not put off from voting Labour as anti-austerity voters may have been in 2015? In part I suspect because Brexit was not the only dominant issue. Labour campaigned on its anti-austerity manifesto, and for many Remain voters this was at least as important as Brexit. This meant that not voting was not an option. There may also have been the realisation that had Labour campaigned to Remain, this would have allowed the Conservatives to make the election a rerun of the Brexit vote, and the distribution of voters by constituency would mean the Conservatives would have won more seats even if the national vote had been evenly split. So in the case of Brexit, but not austerity, triangulation made sense.
Whether this is right or not I have no idea as I am very much an amateur on these issues. I only write about it here because I have not seen this comparison between the two elections made elsewhere. To the extent that Labour’s triangulation on Brexit was tactical, it means if (following May's failed election) the Conservatives move to a softer Brexit (from 8 to 7, say), it is important that Labour moves as well (from 7 to 6) to keep their Remain voters on side.